Cutting Off the Flowers: How Sola Scriptura Distorts the Reformed View of Worship

Reformed Christians often complain about the excessive ritualism of the Catholic Church.  All those holy days, cathedrals, images, Latin phrases, altars, priestly robes, the sign of the cross, etc.  They like to contrast all of this with the "simplicity" of Reformed worship, which avoids anything except the reading and preaching of the Bible, the simple administration of baptism and the Lord's Supper, prayer, and singing of songs.

This attitude ultimately stems from a couple of major points in the Reformed interpretation of Scripture.  Reformed Christians follow the Protestant doctrine of Sola Scriptura, which teaches that the only infallible source of special revelation is the Bible.  Church tradition, and the teaching authority of the Church, are fallible and not to be implicitly trusted.  The practical effect of this view is that Reformed Christians feel justified, and at times required, to pit their own personal interpretations of the Bible over and against the interpretations and applications of the Catholic Church.

The Catholic view is that Scripture comes to us as part of a package deal, which includes also the tradition of the Catholic Church as this has been handed down in the teaching and practices of the Church, and the authority to authentically interpret and apply God's revelation granted by Christ to the bishops of the Church.  This is the historical position of the Catholic Church, which the Reformation had to rebel against in the sixteenth century in order to establish itself.  From the historical, Catholic point of view, the doctrine of Sola Scriptura makes no sense, as it involves ripping the Bible out of its historical context without justification and trying to use it in a way it was never intended to be used.  The result of this is the creation of numerous churches all establishing themselves on the basis of their own private interpretations of the Bible in opposition to the Bible's own natural context in the Catholic Church.  G. K. Chesterton described this situation very memorably in his book, The Thing (London: Sheed and Ward, 1929), in the essay, "Is Humanism a Religion?"

Every great heretic had always exhibit three remarkable characteristics in combination. First, he picked out some mystical idea from the Church's bundle or balance of mystical ideas. Second, he used that one mystical idea against all the other mystical ideas. Third (and most singular), he seems generally to have had no notion that his own favourite mystical idea was a mystical idea, at least in the sense of a mysterious or dubious or dogmatic idea. With a queer uncanny innocence, he seems always to have taken this one thing for granted. He assumed it to be unassailable, even when he was using it to assail all sorts of similar things. The most popular and obvious example is the Bible. To an impartial pagan or sceptical observer, it must always seem the strangest story in the world; that men rushing in to wreck a temple, overturning the altar and driving out the priest, found there certain sacred volumes inscribed "Psalms" or "Gospels"; and (instead of throwing them on the fire with the rest) began to use them as infallible oracles rebuking all the other arrangements. If the sacred high altar was all wrong, why were the secondary sacred documents necessarily all right? If the priest had faked his Sacraments, why could he not have faked his Scriptures? Yet it was long before it even occurred to those who brandished this one piece of Church furniture to break up all the other Church furniture that anybody could be so profane as to examine this one fragment of furniture itself. People were quite surprised, and in some parts of the world are still surprised, that anybody should dare to do so.

The Reformed View

One area in which Sola Scriptura has had problematic effects is in the area of the worship and aesthetics of the Church.  Reformed Christians, reading the Bible, find two ideas:

1. The Regulative Principle of Worship.  This is the idea that we should only worship God in ways that he has prescribed, as opposed to worshiping in unauthorized ways.  This is actually a good idea, but if it is combined with the idea that the Bible gives us everything we need to know about what is authorized by God, it is going to lead us into trouble.

2. Christ is the substance and the fulfillment of the Old Testament ceremonial system, which has been done away with since his coming.  This, too, is a good and right idea, but the application made of it by the Reformed is problematic.

These two ideas are the source of Reformed objections to "Catholic ritualism."  The basic theology goes like this:  In the Old Testament, God prescribed all sorts of rituals and ceremonies for his people.  These rituals and ceremonies pointed towards Christ, who was their fulfillment.  (For example, the whole Old Testament sacrificial system pointed towards Christ who would be the true sacrifice that would take away sins.)  When Christ came, these rituals and ceremonies were abolished (or most of them, at least).  Since Christ has come and we therefore now have the substance, we don't need rituals or ceremonies anymore, except for those very few rituals described clearly in the New Testament, such as baptism and the Lord's Supper (communion).  We have no authorization to add any additional rituals or anything else for the practice of the Church, because God, in the Bible, has not authorized anything else.  And to attempt to add additional rituals or ceremonies is to attempt to go back to Old Testament Judaism and involves a denial of the sufficiency of Christ, and so is to be condemned.

So take a major Catholic holy day like Christmas, for example.  The strictest of the Reformed have historically opposed celebrating Christmas, because it is not prescribed in the Bible.  The Reformed Directory for Public Worship of 1645 puts it this way:

There is no day commanded in scripture to be kept holy under the gospel but the Lord’s day, which is the Christian Sabbath.  Festival days, vulgarly called Holy-days, having no warrant in the word of God, are not to be continued.

In the Reformed view, if we were to take up the celebration of Christmas, we would be "Judaizing"--abandoning Christ for something akin to Old Testament ceremonies.

A pamphlet entitled What is the Reformed Faith?, put out by a conservative Presbyterian denomination, the Orthodox Presbyterian Church, describes the Reformed view clearly:

Some churches today are returning to ceremonial worship. They call it liturgical revival. If they were serious in their claim to be biblical, they would go all the way, adopting the whole Old Testament system. They would even advocate rebuilding the Jerusalem temple. And, if they did, we could at least respect them for consistency. But, of course, these "weak and miserable" (Gal. 4:9) elements of Old Testament worship have no legitimate place in the new covenant church. We need no purple robes, candles, incense, dancing, or dramatic performance. Why? Because these shadowy representations only get in the way of the reality: the privilege of going each Lord's Day—in faithful, commanded worship—right into the heavenly places (Heb. 12:18-29). 

Are we, then, to do as we please—fashioning our own style of worship (while the Old Testament saints had to be careful)? No, we above all should abhor and shun all human inventions. Is this not what underlies the following warning? "See to it that you do not refuse him who speaks. If they did not escape when they refused ... how much less will we....? Therefore, since we are receiving a kingdom that cannot be shaken, let us be thankful, and so worship God acceptably with reverence and awe, for our 'God is a consuming fire' " (Heb. 12: 25, 28-29). 

Worship under the new covenant has been instituted by Jesus. Admittedly, there are few commands regarding, or examples of, corporate worship in the New Testament. The closest thing we have to a formal worship service is found in 1 Corinthians 14, and it focuses on speaking in tongues and prophecy, elements that were appropriate only in the apostolic age (cf. WCF, I:1). Nevertheless, we are able to identify prayer, the reading of the Scriptures, preaching, the singing of praise, the gathering of offerings, and the administration of the sacraments as "all parts of the ordinary religious worship of God" (WCF, XXI:5). . . . 

Reformed worship is beautiful, but it does not have the beauty of sensual things. Rather, it has the beauty mentioned in several of the psalms. "Ascribe to the Lord the glory due his name; worship the Lord in the splendor of his holiness" (Ps. 29:2).

It is for this reason that Reformed worship has always been marked by what some have called "a stark simplicity." The beauty is found in the faithful preaching of the Word of God, in the simple, unadorned, but faithful administration of the sacraments, and in the maintenance of faithful discipline. Reformed people find their delight in truth and in the spiritual things that Christ spoke of when he said that we must worship God in spirit and in truth (John 4:24).

The Catholic Response

Catholics would accept the fundamental idea of the "regulative principle of worship."  Of course we should only worship God in ways he has authorized.  But God's authorization is not only to be found in a private interpretation of Scripture outside its context within the authoritative tradition of the Church.  We don't get to simply read the Bible, find no mention of Christmas, find no justification that we can see to have Christmas, and then declare Christmas illegal because it is without God's authorization.  If the Church's authoritative tradition has interpreted God's revelation such that holy days like Christmas are to be received as a good thing, then this is God's will.  When the Church celebrates Christmas, or uses "purple robes, candles, incense," etc., it is not adding to God's worship without authorization.  It is doing precisely what God has prescribed.

But what about the idea that Old Testament ritualism, feast days, etc., have been done away with because Christ, the substance, has come?  If we are to have rituals in this New Testament age, why are they not prescribed in the New Testament?  After all, God gave very specific instructions about worship in the Old Testament age.

It is here that Sola Scriptura really trips the Reformed up.  According to Catholic teaching, the Holy Spirit has been given to the Church to guide her into all truth.  In Old Testament times, although the Holy Spirit was not entirely absent, yet the people of God were at an earlier stage of development.  A great deal more "spoonfeeding" was going on.  So in the Law of Moses, we see immensely detailed commands regarding worship, politics, and many other things.  The New Testament has no comparable exhaustive law code.  Rather, we see the Church being guided by the Spirit as she works out, over time, the application of what Christ has left to her.  We might say that whereas the worship and life of the Old Testament people were primarily imposed externally through explicit commands, the worship and life of the Church come much more through an internal development as the Holy Spirit guides the Church to apply discerningly the deposit of revelation.  It is in some ways like the difference between a younger child and an adolescent or young adult.  A young child must be given a great many, very specific instructions in every area of life.  As the child gets older, more and more this specific external instruction is replaced by habits of internal discernment.  Parents grant more and more freedom to their children to discern for themselves what is right and best, to apply the principles taught to them over the years, and to manage their own lives.  St. Paul uses this very analogy (Galatians 3:23-25; 4:1-6) in his discussion of the people of God under the Law of Moses vs. the people of God in the new age of Christ:

But before faith came, we were kept under the law, shut up unto the faith which should afterwards be revealed. Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith. But after that faith is come, we are no longer under a schoolmaster. . . . 

Now I say, That the heir, as long as he is a child, differeth nothing from a servant, though he be lord of all; But is under tutors and governors until the time appointed of the father. Even so we, when we were children, were in bondage under the elements of the world: But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law, To redeem them that were under the law, that we might receive the adoption of sons. And because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father.

The Church describes her own view in the Vatican II document Dei Verbum, Chapter 2, Section 8 (footnotes removed):

And so the apostolic preaching, which is expressed in a special way in the inspired books, was to be preserved by an unending succession of preachers until the end of time. Therefore the Apostles, handing on what they themselves had received, warn the faithful to hold fast to the traditions which they have learned either by word of mouth or by letter (see 2 Thess. 2:15), and to fight in defense of the faith handed on once and for all (see Jude 1:3). Now what was handed on by the Apostles includes everything which contributes toward the holiness of life and increase in faith of the peoples of God; and so the Church, in her teaching, life and worship, perpetuates and hands on to all generations all that she herself is, all that she believes. 

This tradition which comes from the Apostles develops in the Church with the help of the Holy Spirit. For there is a growth in the understanding of the realities and the words which have been handed down. This happens through the contemplation and study made by believers, who treasure these things in their hearts (see Luke, 2:19, 51), through a penetrating understanding of the spiritual realities which they experience, and through the preaching of those who have received through Episcopal succession the sure gift of truth. For as the centuries succeed one another, the Church constantly moves forward toward the fullness of divine truth until the words of God reach their complete fulfillment in her. 

The words of the holy fathers witness to the presence of this living tradition, whose wealth is poured into the practice and life of the believing and praying Church. Through the same tradition the Church's full canon of the sacred books is known, and the sacred writings themselves are more profoundly understood and unceasingly made active in her; and thus God, who spoke of old, uninterruptedly converses with the bride of His beloved Son; and the Holy Spirit, through whom the living voice of the Gospel resounds in the Church, and through her, in the world, leads unto all truth those who believe and makes the word of Christ dwell abundantly in them (see Col. 3:16).

A good example of this is the Church's position on the circumcision of Gentiles.  In the Old Testament pattern, we might have expected a law authorizing the non-circumcision of Gentiles to be given very explicitly to the people of God by means of prophets.  But in the New Testament, we find that Christ never even mentions this idea or gives the apostles any specific instructions on the matter.  What we find instead is the Church, over time, being confronted with this issue, calling a council, deciding in that council what is right and best, and announcing her decision with the preface (Acts 15:28), "It seemed good to the Holy Spirit and to us . . ."  Here we see the development of the Church's rules and practices over time by means of the guidance of the Holy Spirit.

The Reformed look in the Bible, and they don't see Christmas.  They conclude that God has not authorized Christmas, and that we should therefore not have it.  They conclude that the reason Christmas and other holy days and rituals are not spelled out in the New Testament is because God wants New Testament worship to be simpler than Old Testament worship, because Christ the substance has come.  But this whole scheme of interpretation is not actually spelled out in the Bible.  The Reformed infer it from the New Testament's lack of many specific instructions regarding worship combined with its abolition of Old Testament ceremonies.  This is a good example of how reading the Bible outside its proper context in the Church's tradition can lead to erroneous conclusions being drawn.

The Catholic faith, interpreting Scripture within its proper context, has a different reading.  The Catholic view is that Old Testament rituals and holy days were done away with not because the people of God should be without such things for the rest of the time of her pilgrimage upon earth, but so that she could develop a new set of rituals and ceremonies appropriate to New Testament times, when Christ, the substance, has come.  For although Christ has come, we are not yet in heaven.  We still await the second coming.  In the meantime, we are not without need of tangible reminders of the presence of God, just like the Old Testament people of God.  Whereas the ceremonies of the Old Testament pointed forward to Christ who would come, the ceremonies of New Testament times point to Christ who has come and Christ who will come again.

We see this development of the worship of the Church already underway within the New Testament itself.  We see that Christ's coming did away with sacrifices, since he was the substantial fulfillment of the sacrificial system, but it replaced them not with no ritual but with the Lord's Supper.  We see that circumcision is done away with, not so that it could be replaced with no ritual, so that we should only focus on the spiritual alone from here on out, but to make room for physical baptism as well.  We see the Church establishing the pattern of meeting on Sunday, which comes eventually, in the last book of the New Testament, to be called "the Lord's Day"--a new, Christian holy day to replace and fulfill the Old Testament Sabbath.  But the Church's development did not cease at the completion of the New Testament.  The Holy Spirit has continued to guide her into all truth and into the application of all truth.  Thus, we see through history new customs, new ceremonies, new rituals, new holy days, being established.  Sometimes we see old customs retired and new ones arise in their place.  There is an ongoing, organic development, like the growth and changing of a living organism, guided by the animating principle within--the Holy Spirit.

The Reformed attempt to restrict the development of the Church to what was already completed within the New Testament is like a person who is given a small, young plant, but instead of allowing the plant to grow and flower, he tries desperately to keep it young, cutting off flowers as soon as they appear, trying to prune it to keep it small, believing that he is protecting his plant from unnatural mutations, while what he is really doing is unnaturally hindering its divinely-designed process of development.  The Reformed attempt to protect the worship of God is well-intentioned, but it works within a context of ignorance and false inferences forced upon it by the unbiblical and unhistorical doctrine of Sola Scriptura.

For more on Sola Scriptura, see here, here, and here.

Published on the feast of St. Thomas More (my patron saint!) and of St. John Fisher

ADDENDUM 3/24/20:  I've been having a conversation recently with a Reformed person, and I thought I'd paste here just a bit of what I've said there because it ties in so nicely with what this post is talking about:

I would say that there is a very large and important truth in what you say, but it is combined with a smaller and more subtle error.

The truth is that the Old Testament priesthood, sacrifices, and other rituals were types and shadows pointing forward to Christ their fulfillment. They performed an important function mediating the people's connection to Christ who was to come, but now that Christ the substance has come, they are abolished. We must not go back to them because that would be to abandon Christ and treat the types and shadows as if they were the reality. All of this is clearly taught in the New Testament, especially in the Book of Hebrews.

The error is in thinking that because Christ the substance has come, there are no longer to be any subordinate intermediaries to mediate Christ and his blessings to us. Christ has come, but we are not yet in heaven. There is an already and a not yet, and we must not lose sight of either. Christ is already with us in a way surpassing the OT, yet there is still a distance between us because we are not yet in the New Heavens and the New Earth. Therefore we do not have grounds to say there is no longer any role at all for subordinate intermediaries. This idea is taught nowhere in the New Testament.

On the contrary, the New Testament indicates the opposite. In the OT, we had the sacrificial system. Now Christ the substance has come, fulfilling that. But this does not mean we now have no rituals by means of which we connect to Christ. Sacrifices are not replaced only with the fact that Christ has come, but also with a new ritual, the Lord's Supper, which is like the sacrifices of the OT in that it is a means of grace that helps connect us to Christ, but instead of pointing forward to Christ who has not yet come it points backwards to Christ who has already come and also forwards to Christ who will come again. ("Do this in memory of me." "We proclaim the death of the Lord until he comes.") It is not that there was ritual in the OT, and now no ritual since Christ has come. It is that there was a certain kind of ritual in the OT, and now that Christ has come there is a new ritual that is changed to reflect and center around and apply that new reality.

In the OT, there was the Sabbath and holy days. Now Christ has come, and they are done away with. But we don't therefore have no holy days at all; we have a new holy day, the Lord's Day, celebrating Christ's resurrection.

In the OT, there were priests, Levites, and elders who ministered to and governed the people. Now Christ has come, and they are done away with. But we don't therefore have no ministers or elders; we have a new system of ministers and elders who help mediate Christ to us by preaching the gospel, administering the sacraments, enacting Church discipline, governing the people, etc.

In the OT, we had circumcision. Now Christ has come, bringing a new time of outpouring of the Holy Spirit and regeneration that fulfills the type of circumcision. And yet this does not mean that there is now no initiatory ritual; rather, we have baptism, through which we are ingrafted into Christ and sealed with the Holy Spirit.

In the OT, we had the Davidic line ruling over the people of God. Now Christ has come and fulfilled that line, being our true and ultimate King. And yet this does not mean we have no earthly civil rulers; rather, we still have the civil authority governing us as a minister of God (Romans 13:1-7), an ambassador to administer, in a limited, civil way, God's justice.

I think the Reformed have erred in taking the biblical truth that Christ the substance has come and fulfilled and abolished the OT types and shadows and inferring from that without Scriptural warrant that this means there are to be no subordinate intermediaries mediating Christ to us in any way.

One more thing: The New Testament does not lay out a long and detailed list of rules regarding worship, sacraments, ministers, etc., unlike the OT which has an enormous amount of such legislation. The Reformed seem often to infer from this that NT worship is to be simpler, with nothing done outside of what is mentioned in the NT. But this inference is not actually taught in Scripture. The Catholic view is that with the people of God "come of age," as it were, there is a new way of development from within led by the Holy Spirit. Instead of God spoonfeeding his people with long lists of explicit instructions, the Holy Spirit guides the Church to develop her worship and her practice internally and organically. So, for example, instead of Christ giving an explicit law about whether or not Gentiles are to be circumcised, we find the Holy Spirit organically guiding the Church from within to arrive at that conclusion once the question has been raised within her historical experience. So there is to be a kind of flowering of the Church's practice and worship, starting from the seed and the small plant we see in the NT, but continuing to flower and grow throughout history, led by the Holy Spirit. Worship is focused now on the substance of Christ that has come, but it is not therefore to be bare and empty of ritual, etc.

The Reformed miss a lot of this, I think, because they rely on Sola Scriptura, assuming the Bible comes as an infallible guide all by itself. The Catholic view, on the other hand, is that the Bible is part of a package deal that also brings with it the Holy-Spirit-guided Tradition of the Church and the Holy-Spirit-guided teaching authority of the Church. The Bible is meant to be interpreted and applied within the context of these other two legs of the three-legged stool, and when the Bible is instead torn out of that original context and attempted to be used independently, it leads to errors in doctrine and practice as fallible humans attempt to make the right inferences from what they see in it to issues not directly addressed. The Catholic position, I would argue, is the historical position of the Church until the Reformation revolted against it.

And then, briefly, I added this:

With regard to the Lord's Supper: The sacrifices of the Old Testament pointed forward to Christ. They could not take away sins, and their being always repeated communicated the message that a Real Sacrifice was needed that could really take away sins.

In the New Testament, Christ has come, that Real Sacrifice. And yet we still have a ritual, the Lord's Supper, which is a means of communicating the grace of Christ to us. The Lord's Supper is not a sacrifice like the OT sacrifices, which were types and shadows fulfilled in Christ. We celebrate the Lord's Supper again and again not because Christ's sacrifice was insufficient, but as a God-appointed means of applying the fruit of Christ's One Real Sacrifice. Christ is not sacrificed again in communion, but his One Sacrifice is made present, is offered up to God on behalf of our sins (just as Christ constantly offers it up to God in his constant intercession), and its fruit is given to the people as they partake of the elements. It is an application of the one, true, and fully sufficient sacrifice of Christ on the cross--not at all something that adds to that sacrifice. But yet, still, we are not in heaven. Christ does not relate to his people entirely without means of subordinate intermediaries in every sense. The Lord's Supper is a means by which Christ applies himself and his blessings to us.

I think of a Judy Rogers song (I don't know if you've heard of Judy Rogers): "Sacraments, given us by Christ, to signify and apply God's covenant to our lives."

The Golden Mean of Church Constitutions

The principle that has come to be known as the "regulative principle of worship" is an absolutely crucial principle in the doctrine of the worship of God.  It teaches us that we are not to use human inventions in divine worship, for God alone has the authority to issue commands for how we are to serve him.  This principle calls into question the many innovations various Christian churches (such as the papists) have added to the worship of God without adequate warrant.

But there is another extreme to avoid on the other side of the principle as well.  It is possible to go too far and, in the name of the regulative principle, to refuse to recognize the church's authority to regulate practices when necessary in order to preserve the principles of the Word of God in areas where various times and customs call for different applications of those principles.  This extreme has, I think, been taken by many who have criticized the Free Presbyterian Church of Scotland, accusing it of being legalistic.  For instance, it is common in the FPCS for ministers and elders to oppose the practice of women wearing trousers.  This strikes many as legalistic.  "Where in the Bible does it say that women can't wear trousers?" they ask.  "I don't see it in there.  This is unbiblical legalism, the addition of man-made traditions to the commandments of God's Word!"

The FP custom here is rooted in Deuteronomy 22:5:  "The woman shall not wear that which pertaineth unto a man, neither shall a man put on a woman's garment: for all that do so are abomination unto the Lord thy God."  So there is a biblical principle here.  It doesn't say anything about trousers, but if trousers are men's clothing, then women would be prohibited by this passage from wearing them.  It is the current dominant opinion within the FPCS that trousers are indeed men's clothing.  In my corner of existence, or the corner I have come from, this is a bit more ambiguous.  Is it unbiblical legalism for ministers and elders to require women to refrain from wearing trousers?  No, it is not, for it is the church's duty to enforce the commands of God.  Sometimes the commands of God deal with specific practices, such as the use of wine (and not just some general liquid) in the Lord's Supper.  Other times, such as here, the rule is general, and it is the custom of the times which determines the proper application.  It is the church's duty to discern the proper application of biblical principles in light of the particular times, and to apply those principles accordingly.  We may disagree with particular applications due to disagreements over how to read the current culture, and perhaps sometimes the elders of the church might be wrong in this regard.  But this is a far cry from a situation where the church simply makes up man-made rules without any serious biblical justification and imposes them on the people of God.  To confuse these two issues is to risk slandering the church when it is in fact acting justly (even when we think it is off-base in terms of its evaluation of the culture).  (Here is an explanation from an FP minister on the FP website of the FP position on clothing, including the trousers issue.)

To give just one more example, what Reformed church today would tolerate a pastor coming into the pulpit wearing a Hawaiian shirt and a purple mohawk?  (OK, some PCA churches might--just teasing.  :-) ).  And yet on what grounds would his action be censured?  Where in the Bible does it say anything about Hawaiian shirts and purple mohawks?  Nowhere, of course.  The justification for censuring this pastor will come from an attempt to apply biblical requirements regarding reverence and proper decorum in light of ideas current in the culture about the social meaning of Hawaiian shirts and mohawks.  And that is my point.  We understand this idea, but sometimes we allow unexamined prejudice to cause us to forget about it and jump to unjust conclusions when it comes to evaluating churches that do things differently from the way we are used to, or who are full of people who have a bit of a different cultural background from our own, or when we disagree with the church in terms of how to understand modern culture (if our cultures are even the same).  Perhaps we, in our part of the world, with the people we tend to hang out with, don't think much about trousers as men's clothing.  But should we write off an entire church simply because the majority of its leaders, for some reason or other, think of trousers differently, and a different cultural understanding of trousers currently prevails in that church?  It is certain that, whatever trousers mean to modern urban Americans in their 20s and 30s, within the culture that currently exists in the FP church trousers are men's clothing.  For a woman, then, to walk into an FP church wearing trousers is for that woman to make a cultural statement--"I have chosen to wear men's clothing"--just as a man walking into the pulpit of most Reformed churches wearing a Hawaiian shirt and a mohawk has made a cultural statement--"I choose to be irreverent."  Certainly, there is a need for understanding on both sides, so that the innocently ignorant should not be condemned along with those who should know better.  But even the innocently ignorant ought to be better instructed and should submit to the prevailing culture within the church once they understand what that is.  This is not legalism--It is charity mixed with a proper recognition of how biblical principles and cultural attitudes and practices go hand-in-hand with each other in human societies.

Below is a selection from John Calvin's Institutes of the Christian Religion, Book IV, chapter 10, translated by Henry Beveridge in 1599, found at the website of the Center for Reformed Theology and Apologetics.  In it, Calvin articulates the idea I have discussed above.  In most of the chapter, Calvin has been insisting on the regulative principle and railing against those who would introduce human inventions into the worship of God, or who would enforce upon the church that which God has not commanded.  But after doing this, Calvin shows a proper respect for balance.  He turns around and criticizes the other extreme that we have been discussing above.  To illustrate the church's right and duty to enforce biblical principles in light of prevailing cultural attitudes and practices, he cites the decrees of the Jerusalem Council.  The Council decreed that Gentiles should refrain from meat offered to idols, from things strangled, and from blood.  But why did they command these things?

The first thing in order, and the chief thing in importance, is, that the Gentiles were to retain their liberty, which was not to be disturbed, and that they were not to be annoyed with the observances of the Law. . . The reservation which immediately follows is not a new law enacted by the apostles, but a divine and eternal command of God against the violation of charity, which does not detract one iota from that liberty. It only reminds the Gentiles how they are to accommodate themselves to their brother, and not to abuse their liberty for an occasion of offence. Let the second head, therefore, be, that the Gentiles are to use an innoxious liberty, giving no offence to the brethren. Still, however, they prescribe some certain thing, viz., they show and point out, as was expedient at the time, what those things are by which they may give offence to their brethren, that they may avoid them; but they add no novelty of their own to the eternal law of God, which forbids the offence of brethren.

According to Calvin, the Jerusalem Council prescribed these limitations on the liberty of the Gentiles as an application of the principle of charity.  Though there were were no universal or unchanging rules requiring their abstaining from some of those things that were proscribed, yet at that time their engaging in such things would have unavoidably involved the wounding of the consciences of their Jewish brethren.  Therefore, the council commanded an appropriate application of the principle of charity for that time and situation.

Calvin mentions some similar things that might be done by some Reformed pastors in his own day, out of concern for protecting the weak consciences of those lately come out of Romanism:

As in the case where faithful pastors, presiding over churches not yet well constituted, should intimate to their flocks not to eat flesh on Friday until the weak among whom they live become strong or to work on a holiday, or any other similar things, although, when superstition is laid aside, these matters are in themselves indifferent still, where offence is given to the brethren, they cannot be done without sin; so there are times when believers cannot set this example before weak brethren without most grievously wounding their consciences. Who but a slanderer would say that a new law is enacted by those who, it is evident, only guard against scandals which their Master has distinctly forbidden?

Calvin goes on, then, to discuss this general idea further.  I have pasted the rest of his words on this subject from this chapter below.  Let us learn from Calvin's comments here to seek the proper mean between the extremes of adding man-made traditions to the worship of God on the one hand and hindering the church from using its proper authority to apply the principles of God's Word to different cultural situations on the other.

But as very many ignorant persons, on hearing that it is impious to bind the conscience, and vain to worship God with human traditions, apply one blot to all the laws by which the order of the Church is established, it will be proper to obviate their error. Here, indeed, the danger of mistake is great: for it is not easy to see at first sight how widely the two things differ. But I will, in a few words, make the matter so clear, that no one will be imposed upon by the resemblance.

First, then, let us understand, that if in every human society some kind of government is necessary to ensure the common peace and maintain concord, if in transacting business some form must always be observed, which public decency, and hence humanity itself, require us not to disregard, this ought especially to be observed in churches which are best sustained by a constitution in all respects well ordered, and without which concord can have no existence. Wherefore, if we would provide for the safety of the Church, we must always carefully attend to Paul's injunction, that all things be done decently and in order, (1 Cor. 14: 40.)

But seeing there is such diversity in the manners of men, such variety in their minds, such repugnance in their judgements and dispositions, no policy is sufficiently firm unless fortified by certain laws, nor can any rite be observed without a fixed form. So far, therefore, are we from condemning the laws which conduce to this, that we hold that the removal of them would unnerve the Church, deface and dissipate it entirely. For Paul's injunction, that all things be done decently and in order, cannot be observed unless order and decency be secured by the addition of ordinances, as a kind of bonds.

In these ordinances, however, we must always attend to the exception, that they must not be thought necessary to salvation, nor lay the conscience under a religion obligation; they must not be compared to the worship of God, nor substituted for piety.

We have, therefore, a most excellent and sure mark to distinguish between those impious constitutions (by which as we have said, true religion is overthrown, and conscience subverted) and the legitimate observances of the Church, if we remember that one of two things, or both together, are always intended, viz., that in the sacred assembly of the faithful, all things may be done decently, and with becoming dignity, and that human society may be maintained in order by certain bonds, as it were, of moderation and humanity. For when a law is understood to have been made for the sake of public decency, there is no room for the superstition into which those fall who measure the worship of God by human inventions. On the other hand, when a law is known to be intended for common use, that false idea of its obligation and necessity, which gives great alarm to the conscience, when traditions are deemed necessary to salvation, is overthrown; since nothing here is sought but the maintenance of charity by a common office.

But it may be proper to explain more clearly what is meant by the decency which Paul commends, and also what is comprehended under order (I Cor. 14:40).

And the object of decency is, partly that by the use of rites which produce reverence in sacred matters, we may be excited to piety, and partly that the modesty and gravity which ought to be seen in all honourable actions may here especially be conspicuous. In order, the first thing is, that those who preside know the law and rule of right government, while those who are governed be accustomed to obedience and right discipline. The second thing is, that by duly arranging the state of the Church, provision be made for peace and tranquillity.

We shall not, therefore, give the name of decency to that which only ministers an empty pleasure; such, for example, as is seen in that theatrical display which the Papists exhibit in their public service, where nothing appears but a mask of useless splendour, and luxury without any fruit. But we give the name of decency to that which, suited to the reverence of sacred mysteries, forms a fit exercise for piety, or at least gives an ornament adapted to the action, and is not without fruit, but reminds believers of the great modesty, seriousness, and reverence, with which sacred things ought to be treated. Moreover ceremonies, in order to be exercises of piety, must lead us directly to Christ.

In like manner, we shall not make order consist in that nugatory pomp, which gives nothing but evanescent splendour, but in that arrangement which removes all confusion, barbarism, contumacy, all turbulence and dissension.

Of the former class we have examples, (1 Cor. 11: 5, 21,) where Paul says that profane entertainments must not be intermingled with the sacred Supper of the Lord; that women must not appear in public uncovered. And there are many other things which we have in daily practice, such as praying on our knees and with our head uncovered, administering the sacraments of the Lord, not sordidly, but with some degree of dignity; employing some degree of solemnity in the burial of our dead, and so forth. In the other class are the hours set apart for public prayer, sermons and solemn services; during sermon, quiet and silence, fixed places, singing of hymns, days set apart for the celebration of the Lord's Supper, the prohibition of Paul against women teaching in the Church, and such like. To the same list especially may be referred those things which preserve discipline, as catechising, ecclesiastical censures, excommunication, fastings, &c.

Thus all ecclesiastical constitutions, which we admit to be sacred and salutary, may be reduced to two heads, the one relating to rites and ceremonies, the other to discipline and peace.

But as there is here a danger, on the one hand, lest false bishops should thence derive a pretext for their impious and tyrannical laws, and, on the other, lest some, too apt to take alarm, should, from fear of the above evils, leave no place for laws, however holy, it may here be proper to declare, that I approve of those human constitutions only which are founded on the authority of God, and derived from Scripture, and are therefore altogether divine.

Let us take, for example, the bending of the knee which is made in public prayer. It is asked, whether this is a human tradition, which any one is at liberty to repudiate or neglect? I say, that it is human, and that at the same time it is divine. It is of God, inasmuch as it is a part of that decency, the care and observance of which is recommended by the apostle; and it is of men, inasmuch as it specially determines what was indicated in general, rather than expounded.

From this one example, we may judge what is to be thought of the whole class, viz., that the whole sum of righteousness, and all the parts of divine worship, and everything necessary to salvation, the Lord has faithfully comprehended, and clearly unfolded, in his sacred oracles, so that in them he alone is the only Master to be heard. But as in external discipline and ceremonies, he has not been pleased to prescribe every particular that we ought to observe, (he foresaw that this depended on the nature of the times, and that one form would not suit all ages,) in them we must have recourse to the general rules which he has given, employing them to test whatever the necessity of the Church may require to be enjoined for order and decency. Lastly, as he has not delivered any express command, because things of this nature are not necessary to salvation, and, for the edification of the Church, should be accommodated to the varying circumstances of each age and nation, it will be proper, as the interest of the Church may require, to change and abrogate the old, as well as to introduce new forms. I confess, indeed, that we are not to innovate rashly or incessantly, or for trivial causes. Charity is the best judge of what tends to hurt or to edify: if we allow her to be guide, all things will be safe.

Things which have been appointed according to this rule, it is the duty of the Christian people to observe with a free conscience indeed, and without superstition, but also with a pious and ready inclination to obey. They are not to hold them in contempt, nor pass them by with careless indifference, far less openly to violate them in pride and contumacy.

You will ask, What liberty of conscience will there be in such cautious observances? Nay, this liberty will admirably appear when we shall hold that these are not fixed and perpetual obligations to which we are astricted, but external rudiments for human infirmity which, though we do not all need, we, however all use, because we are bound to cherish mutual charity towards each other. This we may recognise in the examples given above. What? Is religion placed in a woman's bonnet, so that it is unlawful for her to go out with her head uncovered? Is her silence fixed by a decree which cannot be violated without the greatest wickedness? Is there any mystery in bending the knee, or in burying a dead body, which cannot be omitted without a crime? By no means. For should a woman require to make such haste in assisting a neighbour that she has not time to cover her head, she sins not in running out with her head uncovered. And there are some occasions on which it is not less seasonable for her to speak than on others to be silent. Nothing, moreover, forbids him who, from disease, cannot bend his knees to pray standing. In fine, it is better to bury a dead man quickly, than from want of grave-clothes, or the absence of those who should attend the funeral, to wait till it rot away unburied. Nevertheless, in those matters the custom and institutions of the country, in short, humanity and the rules of modesty itself, declare what is to be done or avoided. Here, if any error is committed through imprudence or forgetfulness, no crime is perpetrated; but if this is done from contempt, such contumacy must be disapproved. In like manner, it is of no consequence what the days and hours are, what the nature of the edifices, and what psalms are sung on each day. But it is proper that there should be certain days and stated hours, and a place fit for receiving all, if any regard is had to the preservation of peace. For what a seed-bed of quarrels will confusion in such matters be, if every one is allowed at pleasure to alter what pertains to common order? All will not be satisfied with the same course if matters, placed as it were on debatable ground, are left to the determination of individuals. But if any one here becomes clamorous, and would be wiser than he ought, let him consider how he will approve his moroseness to the Lord. Paul's answer ought to satisfy us, "If any man seem to be contentious, we have no such custom, neither the churches of God."(I Cor. 11:16).

Moreover, we must use the utmost diligence to prevent any error from creeping in which may either taint or sully this pure use. In this we shall succeed, if whatever observances we use are manifestly useful, and very few in number; especially if to this is added the teaching of a faithful pastor, which may prevent access to erroneous opinions. The effect of this procedure is, that in all these matters each retains his freedom, and yet at the same time voluntarily subjects it to a kind of necessity, in so far as the decency of which we have spoken or charity demands. Next, that in the observance of these things we may not fall into any superstition, nor rigidly require too much from others, let us not imagine that the worship of God is improved by a multitude of ceremonies: let not church despise church because of a difference in external discipline. Lastly, instead of here laying down any perpetual law for ourselves, let us refer the whole end and use of observances to the edification of the Church, at whose request let us without offence allow not only something to be changed, but even observances which were formerly in use to be inverted. For the present age is a proof that the nature of times allows that certain rites, not otherwise impious or unbecoming, may be abrogated according to circumstances. Such was the ignorance and blindness of former times, with such erroneous ideas and pertinacious zeal did churches formerly cling to ceremonies, that they can scarcely be purified from monstrous superstitions without the removal of many ceremonies which were formerly established, not without cause, and which in themselves are not chargeable with any impiety.

A Brief Case for Exclusive Psalmody

My intention here is not to present a full case for exclusive psalmody.  I don't feel a need to do this because of so many others who have done a great job of making that case.  For starters, I would recommend Rev. Brian Schwertley's thorough article on the subject.  I would also recommend Rev. G. I. Williamson's article.  (On the question of musical instruments in worship, Williamson and Schwertley have written another couple of useful articles.)  I would also recommend a book by Michael Bushell entitled Songs of Zion: The Biblical Basis for Exclusive Psalmody.  I myself have not yet read this book (due to the most recent edition being a bit pricy), but I have heard this book recommended so many times from so many people that I'm pretty sure it is a very useful book on the subject.  Another useful article on this subject is the minority report submitted to the General Assembly of the OPC in 1947 while the OPC was investigating the question of songs in worship.  There is also a very helpful website devoted to the defense and practice of exclusive psalmody where many great and useful theoretical and practical resources can be found.

My intention here is simply to make a very brief argument for exclusive psalmody and then make some general comments on the subject.

WHAT IS EXCLUSIVE PSALMODY?

The "regulative principle of worship" tells us to keep three categories of actions distinct: 1. things commanded, 2. things forbidden, and 3. things indifferent.  Since we are not to add to or subtract from God's law (Deuteronomy 12:32, etc.), we must avoid making things forbidden that God has not made forbidden, making things commanded or necessary that God has not made commanded or necessary, etc.  The exclusive psalmody position is simply this:  God has commanded us to sing psalms from the Book of Psalms in our worship of God (both in public and in private and family worship), and he has not commanded us to sing anything else in our worship of God.  Therefore, the singing of psalms in worship is a thing commanded, while the singing of anything else is a thing indifferent (since God has not forbidden the singing of other songs either).  We can distinguish a narrower and a looser definition of the word "worship."  In the broader sense, it includes (or should include) anything at all that we do, for "whether therefore ye eat, or drink, or whatsoever ye do, do all to the glory of God" (1 Corinthians 10:31).  In this sense, mowing the lawn is an act of worship.  In the narrower sense of the word, "worship" refers to acts done in devotion to God that are specifically commanded by God and therefore can be said to be intrinsically pleasing to him (so that he is pleased when they are done and displeased if they are not done).  The exclusive psalmody position is that as the singing of psalms is commanded and no other songs are commanded, only the singing of psalms should be done in the worship of the church (using "worship" in the narrower sense).  This distinction is especially important when we speak of the public worship of the church, because a public worship service is a commanded event.  When the elders of the church call for a public worship service, the congregation is required to attend and participate, and therefore what is done in such a service is considered to be an offering up to God of that which is required by him.  To include the singing of anything other than the psalms in the worship service, then, is to require the people of God to engage in an act of singing that God has not required of them, which is to impose unlawfully upon their consciences and to confuse God's special worship with acts that are indifferent.  And this is to add to God's law, which is forbidden.

IS EXCLUSIVE PSALMODY TRUE?

So now that we have a (hopefully) clear understanding of what exclusive psalmody is, the next question is, Why should we think it to be true?  Well, here's a brief argument (again, not intended to cover all bases and respond to every possible objection):

1. God has commanded us to sing as part of his worship.  This is evident to anyone who picks up the Bible and spends any significant amount of time looking through it.  There are commands to sing all over the Bible (including many in the Book of Psalms itself).  A few examples are Ephesians 5:9, Colossians 3:16, James 5:13, Psalm 104:33, etc., etc.

2. More specifically, God has commanded us to sing the psalms in the Book of Psalms in his worship.  How do we know this?  Well, for one thing, God has given us a worship hymn book right in the middle of the Bible.  If God gives you a hymn book--that is, a collection of songs designed for the worship of his people--it seems rather obvious that you should use it.  The first time I ever heard a psalm sung in worship as such (so far as I can recall) was when I was 22 years old.  I thought it was odd to hear people actually singing a part of the Bible.  How strange!  Now, I look back at my past and around at the various churches and think it odd that it occurs to so few evangelical Christians today (as opposed to in the past, when psalm-singing was normal and pretty much universal in the church) that God might actually want us to sing the book of songs that he gave us.

God has specifically commanded his people to use the book of songs he has given them in his worship.  In addition to his general command to sing, he has specifically prescribed the Book of Psalms in his worship.  See, for example, 2 Chronicles 29:30:

Moreover Hezekiah the king and the princes commanded the Levites to sing praise unto the Lord with the words of David, and of Asaph the seer. And they sang praises with gladness, and they bowed their heads and worshipped.

This is clearly a reference to what we now call "The Book of Psalms."  It may not have been completed at that time, but the Chronicles passage clearly implies a collected book of songs for use in worship, and as we have such a collected book in our Bible which has a number of songs written by David and Asaph in it, I think it is safe to say that the Book of Psalms is the current, completed version of this collection.  There are other inspired songs recorded in the Scriptures elsewhere, some of which made it into the Book of Psalms and some of which didn't.  The distinction seems to be that some songs were intended for specific circumstantial use (like the song of Miriam in Exodus 15) while others were intended for the ongoing, regular worship of the people of God.  The church as a whole, in its ongoing regular worship, is to use the Book of Psalms, but there is no evidence that it is commanded to sing the songs not included in it.  In conclusion, the evidence of the Old Testament tells us that the people were commanded as part of their ongoing worship to sing the psalms, but it never gives us any indication that they were commanded to sing anything else.  Therefore, we can conclude based on the Old Testament data that the singing of psalms is commanded and the singing of other songs is indifferent.

But is singing from the Book of Psalms required in New Testament times, or only in Old Testament times?  A good rule of thumb when dealing with God's commands, considering that we are not to add to or diminish from his law, is that if God commands us to do something, we continue to observe that command until or unless God gives us some indication that we are to stop.  There is no evidence in the Scriptures that we are no longer to use the Book of Psalms in worship.  It is still there in our Bibles.  There is no obvious reason arising from it why we shouldn't sing it anymore.  One argument that might be made against using it in New Testament times is that the command to sing psalms was a part of the ceremonial law which was abrogated by the coming of Christ.  It is true that the singing of psalms was a part of the ceremonial worship of the OT people of God, and it is true that ceremonial worship as such (including, for example, the Temple worship, animal sacrifices, incense, etc.) was abrogated with the coming of Christ.  However, not all aspects of Old Testament worship have been abrogated.  The New Testament tells us that some elements of worship, such as having a holy convocation once a week, reading the Scriptures, the preaching of the Scriptures, and other things continue in New Testament times.  The command to sing is also repeated in the New Testament (as I noted earlier), which tells us that the element of singing in worship continues in New Testament times.  Does the New Testament alter the Old Testament's instructions as to what we should sing?  No, it doesn't.  It never annuls the Book of Psalms, nor does it provide anything else in addition to it.  Therefore, it follows that the New Testament people of God should continue to sing the Book of Psalms in their worship.

3. There is no evidence that anything besides the Book of Psalms is commanded for use by the people of God in their ongoing, regular worship.  There is not much to add here.  There is not even the slightest, clear hint of any command to sing uninspired songs in worship anywhere in the Old or New Testaments.  Some people think that there is such a command in Ephesians 5:9 and Colossians 3:16, because there Paul commands us to sing "psalms, hymns, and spiritual songs."  Well, isn't that a clear command to sing not just psalms, but hymns and spiritual songs as well?  "Psalms" refers to the songs in the Book of Psalms, "hymns" refers to the songs of John Newton, Isaac Watts, etc., and "spiritual songs" refers to . . . contemporary worship songs like "Shine, Jesus, Shine"?  Obviously, people who make this argument often don't think it out fully.  The fact is that "psalms," "hymns," and "songs," are all words used by the Scripture to refer to the songs in the Book of Psalms!  Here is Rev. Schwertley on this point (footnote references added), pp. 11-12:

When we examine the Septuagint, we find that the terms psalm (psalmos), hymn (humnos), and song (odee) used by Paul clearly refers to the Old Testament book of Psalms and not ancient or modern uninspired hymns or songs. Bushell writes, “Psalmos ...occurs some 87 times in the Septuagint, some 78 of which are in the Psalms themselves, and 67 times in the psalm titles. It also forms the title to the Greek version of the psalter.... Humnos ...occurs some 17 times in the Septuagint, 13 of which are in the Psalms, six times in the titles. In 2 Samuel, 1 & 2 Chronicles and Nehemiah there are some 16 examples in which the Psalms are called ‘hymns’ (humnoi) or ‘songs’ (odai) and the singing of them is called ‘hymning’ (humneo, humnodeo, humnesis).... Odee ...occurs some 80 times in the Septuagint, 45 of which are in the Psalms, 36 in the Psalm titles.” [Michael Bushell, The Songs of Zion, pp. 85-86.] In twelve Psalm titles we find both “psalm” and “song”; and, in two others we find “psalm” and “hymn.” “Psalm seventy-six is designated ‘psalm, hymn and song.’ And at the end of the first seventy two psalms we read ‘the hymns of David the son of Jesse are ended’ (Ps. 72:20). In other words, there is no more reason to think that the Apostle referred to psalms when he said ‘psalms,’ than when he said ‘hymns’ and ‘songs,’ for all three were biblical terms for psalms in the book of psalms itself.” [G.I. Williamson, The Singing of Praise in the Worship of God, p. 6.] To ignore how Paul’s audience would have understood these terms and how these terms are defined by the Bible; and then instead to import non-biblical modern meanings into these terms is exegetical malpractice.

So there is no evidence from these passages for a command to sing uninspired songs as a part of worship.  But what about other inspired songs recorded in the Scriptures?  I dealt with this a bit earlier.  While there are other songs and poems recorded in the Scriptures outside the Book of Psalms, there is no evidence that these songs are commanded to be used in the regular, ongoing worship of the people of God, unlike with the Book of Psalms.  Therefore, their presence is Scripture does not constitute evidence that we are commanded to sing them in our worship.  As I said earlier, the fact that we are given a collected book of songs for worship and these other songs are not included in it points to these songs as having been deliberately and specifically left out of the songs commanded to be sung in the ongoing worship of the people of God.

4. Therefore, in light of the above, we must conclude that we are commanded to sing the Book of Psalms as part of our worship and that we are not commanded to sing anything else.  Therefore, we should sing only the Book of Psalms in our worship (using "worship" in the narrower sense) and particularly in the public worship of the church.  The Westminster Confession (chapter 1, section 5) captures this well when it describes the ordinary elements of Christian worship (leaving out prayer, because it is addressed elsewhere in the same chapter):

The reading of the Scriptures with godly fear; the sound preaching and conscionable hearing of the Word, in obedience unto God, with understanding, faith, and reverence; singing of psalms with grace in the heart; as also, the due administration and worthy receiving of the sacraments instituted by Christ; are all parts of the ordinary religious worship of God: beside religious oaths, vows, solemn fastings, and thanksgivings, upon special occasions, which are, in their several times and seasons, to be used in a holy and religious manner. 

The Westminster Form of Presbyterial Church-Government also puts this well in its description of the "ordinances in a particular congregation":

THE ordinances in a single congregation are, prayer, thanksgiving, and singing of psalms, the word read, (although there follow no immediate explication of what is read,) the word expounded and applied, catechising, the sacraments administered, collection made for the poor, dismissing the people with a blessing.

We are not simply commanded to sing in a general sense, but it is the "singing of psalms" that is commanded.

WHAT ABOUT INSTRUMENTAL MUSIC?

I want to add to my above argument one more piece relating to instrumental music.  Again, see my links above to delve into a deeper look at the issue, but, in short, the main argument against using musical instruments in worship is that they are not commanded to be used in worship.  Instrumental music was a part of the ceremonial worship of the Old Testament, but that has been abolished in New Testament times, and there is no New Testament command to continue it.  Therefore, we cannot consider it commanded, etc.  Sometimes people argue that it can still be included because it is not a separate element of worship but rather a part of singing, perhaps as it provides accompaniment that aids in singing.  But the fact is that it is indeed a separate element.  It provides something that singing does not.  It adds its own unique contribution when it is used in worship.  It has the ability to stir the emotions in a unique way, for example.  It was very distinctly commanded and organized in the Old Testament dispensation (see 2 Chronicles 29, for example).  Also, singing is quite possible without it, so it is not required as part of the essence of singing.  Therefore, there ought to be a command for its use if it is going to be used in the worship of the church.  (Under normal circumstances at least--philosopher that I am, I can see a hypothetical argument being made that there might be circumstances where people are so awful at singing that they simply cannot do it without some instrumental accompaniment.  In such a case, perhaps a minimal accompaniment could be allowed.  But does this situation ever actually exist in reality?  Unless accompaniment can be shown to be truly necessary, I think it should be avoided because of the natural tendency of musical instrumentation to add its own distinct element to the experience of worship.)

A BRIEF CONCLUDING COMMENT

Many comments could be made upon the benefits and implications of exclusive psalmody and the regulative principle of worship.  One comment that comes to my mind at this time is how the regulative principle, and its implication in exclusive psalmody and the avoidance of musical instrumentation in worship, keeps Christians from lording over the consciences of other Christians.  I enjoy psalm singing, but I also enjoy many other types of music.  Just this morning, I was listening to Enya, who is one of my favorite artists.  I also enjoy classical, traditional Japanese, Middle Eastern, Medieval and Renaissance, some contemporary Christian, celtic, and other kinds of music.  I'm quite sure that not everyone shares all of my tastes in music.  And I know I don't share a taste for all the music that suits other people either (such as country music, which I take on pure faith that some people somehow actually find enjoyable).  If I were to craft a worship service according to my taste in music, who knows what sorts of weird elements I might bring into it?  What songs would I use?  What forms of music would I employ?  What instruments would I use?  The end result would be that I would be imposing my own musical preferences on the entire congregation, forcing them to employ in their worship things that I personally find useful and enjoyable but which are not commanded and which may not be useful or enjoyable for others.  Not everyone gets out of my music what I get out of it.  It is not my place to impose that which is unique to myself on everyone else as if it were on par with what God has commanded for all.  The regulative principle reminds us to keep up a firm distinction between the worship of the people of God, which is something we all have in common together and which is intrinsically pleasing to God, and other activities we as individuals (or as voluntary groups) may find enjoyable and useful to engage in but which are not essential elements in God's commanded worship for his people.  Employing the regulative principle in worship allows the people of God to find unity in what God has given to all of us and to avoid imposing ourselves as lords over each other (which usually leads to schisms in the church).  And it allows God to define his own worship that is intrinsically pleasing to him, which is something that is his prerogative alone.

UPDATE 6/18/14:  For those interested in the history of psalm-singing in the worship of the church (in addition to the resources already cited above), here, here, and here are a few articles for starters.  The articles do not agree with each other in every point, but they are useful as a place to dive into further historical investigation on this subject.

A (Hopefully) Clear Explanation of the Regulative Principle of Worship

Observe and hear all these words which I command thee, that it may go well with thee, and with thy children after thee for ever, when thou doest that which is good and right in the sight of the Lord thy God. When the Lord thy God shall cut off the nations from before thee, whither thou goest to possess them, and thou succeedest them, and dwellest in their land; Take heed to thyself that thou be not snared by following them, after that they be destroyed from before thee; and that thou enquire not after their gods, saying, How did these nations serve their gods? even so will I do likewise. Thou shalt not do so unto the Lord thy God: for every abomination to the Lord, which he hateth, have they done unto their gods; for even their sons and their daughters they have burnt in the fire to their gods. What thing soever I command you, observe
to do it: thou shalt not add thereto, nor diminish from it. (Deuteronomy 12:28-32)

The light of nature showeth that there is a God, who hath lordship and sovereignty over all, is good, and doth good unto all, and is therefore to be feared, loved, praised, called upon, trusted in, and served, with all the heart, and with all the soul, and with all the might. But the acceptable way of worshipping the true God is instituted by Himself, and so limited by His own revealed will, that He may not be worshipped according to the imaginations and devices of men, or the suggestions of Satan, under any visible representation, or any other way not prescribed in the holy Scripture.  (Westminster Confession of Faith 21:1)

These two passages, one from Scripture and the other from the Westminster Confession, well summarize the basic idea of the regulative principle of worship.  God is to be worshiped only as he has commanded and not in ways he has not commanded.

DEFINING TERMS

Although a lot of people have argued against this principle, it is actually quite common-sensical when its basic meaning is clarified, terms are defined adequately, etc.  So let's start by defining "worship."  There is a broader and a narrower meaning of the term "worship," and the regulative principle applies to both.  The broader meaning of "worship" is simply "service to God" of any kind.  Whenever we offer up to God that which is pleasing to him and which he has commanded us to do, we are engaging in "worship" or "service."  "Worship" or "service to God," then, in this sense, is nothing other than a synonym for "obedience to the commandments of God."  This broader idea of "worship" is specifically addressed in the Westminster Confession under the heading "Of Good Works":  "Good works are only such as God hath commanded in His holy Word, and not such as, without the warrant thereof, are devised by men, out of blind zeal, or upon any pretence of good intention" (WCF 16:1).

The narrower category of "worship" is the subset of the category of "good works" which has to do with specifically devotional acts.  Thus, in this sense, partaking of the Lord's Supper is an act of "worship" in a way that caring for the poor is not, because, while both are commanded, the former is a devotional act directed immediately towards God.

THE THREE CATEGORIES

There are three categories of activities that humans have the ability to engage in:  1. Things that are commanded.  2. Things that are indifferent.  3. Things that are forbidden.  The first and the last of these categories are pretty straightforward.  Our lives belong to God to do his will, and he has given us commands as to how we are to live.  When we obey these commands (which would include not doing things that are forbidden as well as doing things that are positively commanded), we do that which is pleasing to God.  On the other hand, when we do that which God has forbidden us to do (which would include both doing things positively forbidden as well as not doing things positively commanded), we do that which is displeasing to God.

The category of "things indifferent" requires a little more explanation.  The idea of "things indifferent" does not imply that there are things we can do for no reason at all, as if we are permitted by God to waste our lives by engaging in worthless activities.  This is too often what the modern idea of "entertainment" or "amusement" means.  In our modern western societies based on Naturalism (the idea that empirical nature is either all there is or at least all that we can know about), there is no concept that we are creatures of God who belong to him and who are obligated to live according to his will.  We are thought to be (as far as can be known) nothing other than accidental by-products of mindless processes, and therefore we owe no obligation to any standards higher than our own desires.  In this kind of an ideological context, the purpose of life is nothing more than simply to find a way to amuse ourselves until we die.  The centrality of "entertainment" to modern western culture is thus not surprising.

But this has nothing to do with what we mean by the category of "things indifferent."  Since our lives belong to God, we are to live them entirely for his glory and in the pursuit of doing his will.  "Whether therefore ye eat, or drink, or whatsoever ye do, do all to the glory of God" (1 Corinthians 10:31).  However, sometimes there are a variety of legitimate ways to live for God in a particular area of life.  Almost always there is some flexibility as to how things are to be done, and that flexibility is more or less in some cases than in others.  For example, we are commanded by God to worship him in a public gathering of the church on the first day of the week (the Lord's Day).  But we are not told precisely at what times we are to meet.  Should our morning service be at 9:00 AM, or at 10:00, or at 11:00, etc.?  The Bible does not say.  So we do what makes the most sense.  And sometimes more than one option makes sense, and so we do whatever suits us best.

For another example, we are commanded to love our neighbors as ourselves, help those in need, etc.  But this can often be done in many different ways.  Does this mean that I ought to be doing service in a soup kitchen downtown?  Perhaps.  But not necessarily.  There are other ways people are in need and other ways to help them.  I could give many more examples of this kind of thing.  This is what we mean by "things indifferent."  Situations often arise when more than one choice is legitimate, and in these cases I may choose to do what seems best.  Choosing option A is not a sin, but then neither is choosing option B instead.

The category of "things indifferent" is often relative to the various entities involved in doing the evaluating.  For example, I have more immediate control over my own life than do the elders of the church.  I am under the authority of church elders, but my own authority over my life (self-government) is much closer to my everyday doings and much more involved in the details of my life.  Thus situations often arise when, considering my own responsibility of self-government, I really ought to choose option A over option B and it would be wrong of me to choose option B, and yet my obligation here arises from very specific circumstances of my own life, personality, etc., in such a way that authorities more distant from myself ought not to issue commands in the matter.  For example, perhaps I know that I really ought not to have "just one more cookie."  I've had enough already, and it would be an inappropriate use of resources, bad for my health, etc., for me to have another one.  Relative to my own self-government, it is not an indifferent thing whether or not I eat another cookie.  But relative to church government, it should be viewed as a thing indifferent.  It would not be appropriate for the elders of the church to try to micromanage the diets of the members of the church to that sort of degree.

The relationship between things commanded (or necessary) and things indifferent is well expressed in the Westminster Confession:

The whole counsel of God concerning all things necessary for His own glory, man's salvation, faith, and life, is either expressly set down in Scripture, or by good and necessary consequence may be deduced from Scripture: unto which nothing at any time is to be added, whether by new revelations of the Spirit, or traditions of men. Nevertheless we acknowledge the inward illumination of the Spirit of God to be necessary for the saving understanding of such things as are revealed in the Word: and that there are some circumstances concerning the worship of God, and government of the Church, common to human actions and societies, which are to be ordered by the light of nature and Christian prudence, according to the general rules of the Word, which are always to be observed.  (WCF 1:6)

CONFUSING THE CATEGORIES

So we have the three categories of commanded, indifferent, and forbidden.  I like to think of the regulative principle of worship, in its broadest sense, as simply the principle of keeping these three categories distinct.  We should not treat commanded things as if they are indifferent.  We should not treat indifferent things as if they are commanded.  We should not treat forbidden things as if they are commanded or indifferent, or vice versa.  And so on.  We can confuse these categories in two main ways:

1. We confuse the categories when, in our own lives or in our own thinking, we put things in the wrong category.  For example, the Scriptures nowhere command us to make a pilgrimage to Jerusalem (at least not in New Testament times).  Neither does it forbid us to go to Jerusalem.  Generally speaking, whether or not a person goes to Jerusalem is a thing indifferent.  If, then, I were to come to hold the opinion that it is a necessary duty for men to make a pilgrimage to Jerusalem and thus to feel myself duty-bound to do it, I would be in violation of the regulative principle.

2. We can also confuse the categories and violate the regulative principle by misusing our authority over others.  To use the same example, if a church session or council were to command or require members of the church to make a pilgrimage to Jerusalem as a necessary action, the council would be abusing its authority, for what God has not commanded cannot be commanded by those to whom God has delegated authority.  God has not given authority to the church to simply make up commands out of its imagination and impose them on people.  As the passage earlier quoted from Deuteronomy 12 says, we are not to add to nor take away from God's commands.  Similarly, we are not to turn commanded things into things indifferent.  If the church were to tell members that they are not required to regularly attend worship or to receive communion (when otherwise qualified to do so), this would be a violation of the regulative principle, as the church has no authority to negate what God has commanded any more that it can require what God has not commanded.  I think the OPC's Directory for the Public Worship of God captures well how the proper use of church authority (and the same principle applies to all other human authority as well--civil, family, etc.) is bound up with respect for the regulative principle of worship:

God may not be worshiped according to human imaginations or inventions or in any way not prescribed by his Word, nor may the church require her members to participate in elements of worship that God's Word does not require. Only when the elements of worship are those appointed in God's Word, and the circumstances and forms of worship are consonant with God's Word, is there true freedom to know God as he is and to worship him as he desires to be worshiped.  (DPW IB6b)

Throughout the Scriptures, there are warnings against altering the law of God by adding to it or taking away from it--taking that which God has commanded and making it indifferent or forbidden, or taking that which is indifferent or forbidden and making it commanded, etc.  One classic example is Jesus's confrontation with the Pharisees in Mark 7:5-13:

Then the Pharisees and scribes asked him, Why walk not thy disciples according to the tradition of the elders, but eat bread with unwashen hands? He answered and said unto them, Well hath Esaias prophesied of you hypocrites, as it is written, This people honoureth me with their lips, but their heart is far from me. Howbeit in vain do they worship me, teaching for doctrines the commandments of men. For laying aside the commandment of God, ye hold the tradition of men, as the washing of pots and cups: and many other such like things ye do. And he said unto them, Full well ye reject the commandment of God, that ye may keep your own tradition. For Moses said, Honour thy father and thy mother; and, Whoso curseth father or mother, let him die the death: But ye say, If a man shall say to his father or mother, It is Corban, that is to say, a gift, by whatsoever thou mightest be profited by me; he shall be free. And ye suffer him no more to do ought for his father or his mother; Making the word of God of none effect through your tradition, which ye have delivered: and many such like things do ye.

Jesus condemned the Pharisees both for adding to the commands of God by putting their tradition into the category of things commanded without warrant from Scripture, and for taking that which God had commanded in Scripture and making it a thing indifferent.  In short, the Pharisees violated the regulative principle of worship.

Another classic example is Paul's exhortation to the Colossians not to add to the commands of God either by going back to the ceremonial law of Judaism or by making up new traditions out of their own imaginations:

Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days: Which are a shadow of things to come; but the body is of Christ. Let no man beguile you of your reward in a voluntary humility and worshipping of angels, intruding into those things which he hath not seen, vainly puffed up by his fleshly mind, And not holding the Head, from which all the body by joints and bands having nourishment ministered, and knit together, increaseth with the increase of God. Wherefore if ye be dead with Christ from the rudiments of the world, why, as though living in the world, are ye subject to ordinances, (Touch not; taste not; handle not; Which all are to perish with the using;) after the commandments and doctrines of men? Which things have indeed a shew of wisdom in will worship, and humility, and neglecting of the body: not in any honour to the satisfying of the flesh.  (Colossians 2:16-23)

Paul warns the Colossians that adding to the commands of God is not only wicked, but also useless.  The Colossians are tempted to think that God's Word doesn't provide sufficient aids to sanctification, and that the defect must be supplied by their own traditions; but Paul warns them that although their "will worship, and humility, and neglecting of the body" might seem superficially to be able to advance the sanctification of man, in reality they cannot satisfy the flesh--that is, they cannot provide the needed sanctifying power.  God has given us all we need in his Word, and any attempted additions to this are not only useless but harmful.  As an analogy, we can imagine a recipe written up by an infallible cook.  Any changes made to that recipe by fallible cooks cannot help but can only harm the outcome, no matter how wise those changes may seem to their fallible minds.

CASE STUDY: EXTRA-BIBLICAL HOLY DAYS

In order to make the above discussion more concrete, let's apply it briefly to a particular case: the issue of extra-biblical holy days.

There were many holy days commanded for the people of God in Old Testament times.  However, as the Colossians passage quoted above illustrates, these holy days have been abolished in New Testament times, having been shadows pointing forward to Christ.  The only holy day commanded in Scripture for New Testament times is the Lord's Day on the first day of the week.  (This is not the place to go into an argument for this point, but see this article by Rev. Brian Schwertley for some good argumentation on the subject.)  Throughout the history of the church after the time of the apostles, however, various new holy days were introduced into the practice of the church, such as Christmas and Easter.  These days (and many others) were mandated in the church during the Middle Ages.  At the time of the Reformation, many Reformed churches abolished them, but the continental Reformed churches waffled back and forth on some of them for a while, eventually codifying a few of them into the regular practice of the church at the Synod of Dordt around 1618-19 (see this article by a continental Reformed minister for a historical account of how this happened).  The Reformed Church of Scotland, on the other hand, rejected all of them from the beginning and never embraced them.

So the question is this:  Is it in accord with the regulative principle of worship to observe extra-biblical holy days like Christmas and Easter?

Well, let's start by being clear as to what it means to "observe" a holy day like Christmas or Easter (we'll focus on Christmas to make discussion easier).  Let's describe this idea by dividing it into two parts:  1. For a person to "observe" Christmas means that he sets aside December 25 (at least in the west) in order to focus special attention on the birth of Christ.  2. For a church to "observe" Christmas means that the elders of the church set aside December 25 as a special day to focus on the birth of Christ, usually partly by means of having a special worship service on that day and perhaps commanding members to participate in it.

So is any of this in violation of the regulative principle of worship?  First of all, is there anything wrong with a person voluntarily deciding to spend December 25 focusing his thoughts on the birth of Christ?  No, there is nothing necessarily wrong with this.  What days or times we devote to thinking about some particular topic is, in general, a thing indifferent.  As long as we understand that it is a thing indifferent when we do it, there is nothing wrong with this (speaking generally--obviously, in some particular situations there might be something wrong with it relating to particular details of an individual's life).

But what if we begin to think of it as a thing that is necessary?  At this point, we are in violation of the regulative principle unless we can prove that God has commanded in Scripture that it is a duty to focus on the birth of Christ on December 25.  We cannot add to God's law by making a duty what God has left indifferent.  Sometimes we might be tempted to do this subtly:  "Well, observing Christmas isn't strictly necessary (such a harsh word), but it is really good for my spiritual life, such that my spiritual life would suffer and be significantly impoverished if I didn't do it."  Is it a thing indifferent to cause one's spiritual life to be significantly impoverished or to suffer?  Of course not!  Therefore this is simply a roundabout and disingenuous way of saying that the observance of Christmas is a necessary duty.  But can we really prove that from Scripture (either from what is "expressly set down in Scripture, or by good and necessary consequence may be deduced from Scripture")?  I don't see how.  Do we really have evidence that a person's spiritual life is incomplete if he doesn't celebrate Christmas?  Are we willing to say that all those (such as the historic Presbyterians and Puritans) who don't celebrate Christmas have had impoverished spiritual lives and have not been taking care of their spiritual lives as much as they should?  Without such evidence, we have to conclude that the idea that Christmas is an important part of one's spiritual life is not a Scriptural idea but one invented by human imagination.  And thus to think of the observance of Christmas in this way is to make commanded or necessary that which is indifferent, and thus to violate the regulative principle of worship.

Well then, is it a violation of the regulative principle of worship for the church as a body to observe Christmas?  Since the Scriptures nowhere command the observance of Christmas, and since the observance of Christmas cannot be proved to be necessary to fulfill some divine command that is present in Scripture, we must conclude that it is a violation of the regulative principle of worship for a church to command the observance of Christmas on church members.  There is no biblical reason why it is necessary to separate December 25 as a special day on which the focus should be placed on the birth of Christ, and so the church cannot require it or make it necessary.  Of course, the church also should not forbid church members from focusing on the birth of Christ on December 25, so long as they do not do it as a commanded duty but only as something voluntary.

But what if the church does not command members to participate in the observance of Christmas, but simply has a special worship service in order as a body to observe Christmas while leaving it voluntary for members to participate or not?  This may at first glance seem to allow the church to escape the difficulty, for it is not commanding its members to do anything.  But I think that if we examine this scenario more carefully, we will see that it involves a bit of double-speak.  If the church does something as a body under the authority of the church session, surely that involves a claim from the elders of the church that doing this thing is important for the church to do.  It would be ridiculous for the elders of the church to go through the trouble of putting together a special religious service and then, upon being asked why they are doing this, to reply, "Oh, for no good reason."  This would be a waste of the time and resources of the church.  When a church observes Christmas as a body, even when it does not strictly speaking require participation from members, it still sends a clear message that the observance of Christmas is an important thing for the Body of Christ to do, and this implies that those who do not participate are in some sense neglectful of their spiritual life.  They are not, strictly speaking, commanded to participate, but how can their non-participation be regarded when they are refraining from participating in something the church has declared is important enough to pursue as a body?  While the words say that participation is not necessary, the actions imply that those who do not participate are missing out on something that the church ought to be doing.

But cannot the church command days and times to be set apart for particular purposes in certain circumstances in order better to carry out the ministry of the church?  For example, would it violate the regulative principle for the church to set aside a certain Wednesday in February in order to deliver a lecture on some particular doctrinal topic?  No, this would not violate the regulative principle, because it is evident that sometimes circumstances arise in which the teaching ministry of the church requires some time to be set aside other than the regular Sunday worship services.  When this can be shown to be necessary, there is nothing wrong with doing it.  The problem with something like the observance of Christmas is that it involves in its very essence the idea that there is something special about the particular day and that there is some necessity to have a regular ritual in which that particular day is made the focus of special attention.  If a lecture is held on February 17, nobody thinks that this involves some kind of special observance of that particular day as special.  Its being set aside for a particular use is purely logistical in nature rather than being viewed as somehow necessary per se as a part of the ongoing worship and service of the church.  Of course, it is evident that these issues can be tricky and subtle, and that much care and discernment is required to think rightly about them.  We should pray to exercise such discernment, but we should not make the difficulty of some particular cases an excuse to throw discernment out the window and just do whatever we want.  The case here is parallel to that of ethics.  There are cases of ethics that are difficult and require much careful thought and great discernment, but that cannot be used as an excuse to throw ethical discernment out the window and declare that "anything goes."

Of course, we can also add to the above discussion the fact that the New Testament specifically condemns the idea that it is necessary to observe holy days outside the Lord's Day.  I have already referred above to Colossians 2:16-23.  We can add to that Galatians 4:8-11:

Howbeit then, when ye knew not God, ye did service unto them which by nature are no gods. But now, after that ye have known God, or rather are known of God, how turn ye again to the weak and beggarly elements, whereunto ye desire again to be in bondage? Ye observe days, and months, and times, and years. I am afraid of you, lest I have bestowed upon you labour in vain.

So we can say that the Scriptures not only do not command holy days outside the Lord's Day to be observed, but they positively forbid the counting of such days as objectively special or holy.  But notice that we arrived above at this conclusion without having to refer to passages that positively condemn the idea of the necessary observance of extra-biblical holy days.  Although these passages confirm our conclusion, we already knew it was correct simply on the basis that the Scriptures nowhere command the observance of such holy days.

In light of a clear investigation of the facts regarding the observance of extra-biblical holy days like Christmas, the position taken by the historic Reformed Church of Scotland, as expressed in the Westminster Directory for the Public Worship of God, seems warranted:

THERE is no day commanded in scripture to be kept holy under the gospel but the Lord's day, which is the Christian Sabbath.

Festival days, vulgarly called Holy-days, having no warrant in the word of God, are not to be continued.

Nevertheless, it is lawful and necessary, upon special emergent occasions, to separate a day or days for publick fasting or thanksgiving, as the several eminent and extraordinary dispensations of God's providence shall administer cause and opportunity to his people.

The disagreement between the continental Reformed churches and the heirs of the Reformed Church of Scotland on this matter has for the past few centuries created a barrier to full unity between these two traditions.  A more careful application of the regulative principle of worship is in order to help resolve the schism.

CONCLUSION

In conclusion, the regulative principle of worship is much more straightforward and rooted in Scriptural common sense than many people think.  I remember when I used to struggle with this issue, I had trouble understanding why worship could only consist of things commanded in the Scriptures.  Can't we love God with all of our lives, even when we do things that are indifferent rather than commanded?  Yes, of course we can, and should (actually, we are required to do so, as I showed earlier).  The regulative principle of worship does not mean that I can never do anything indifferent to the glory of God.  It simply requires that I keep the three categories of commanded, indifferent, and forbidden distinct.  I can glorify God by means of something indifferent.  What I cannot do is glorify God by turning something indifferent into something commanded (or vice versa, etc.).  For example, I am free to sing man-made hymns to the glory of God.  This is not a bad thing to do at all.  What I can't do is treat the singing of man-made hymns as if it is a duty I am commanded to perform or as if it were something that is per se pleasing to God (in such a way that God would be displeased if I didn't do it).  Nor can I make it a duty for others to do it or command or require them to do it.  Why?  Because the singing of man-made hymns is nowhere commanded in Scripture, nor does it follow by good and necessary consequence from any command of Scripture.  (Of course, I have here raised a contentious issue.  I will not deal with it at this time, however, but refer readers here as a starting point for further investigation.)  The regulative principle of worship is not some immensely complex theological construct.  It is nothing more than the realization that God is the ultimate moral authority of the universe and that we exist to please him, and that therefore only he ultimately can declare to us what our duty is (and what sin is), and we have no right to add to it nor take away from it.