The civil magistrate may not assume to himself the administration of the Word and sacraments, or the power of the keys of the kingdom of heaven: yet he hath authority, and it is his duty, to take order, that unity and peace be preserved in the Church, that the truth of God be kept pure and entire; that all blasphemies and heresies be suppressed; all corruptions and abuses in worship and discipline prevented or reformed; and all the ordinances of God duly settled, administered, and observed. For the better effecting whereof, he hath power to call synods, to be present at them, and to provide that whatsoever is transacted in them be according to the mind of God.
I have read the above-quoted portion of the Westminster Confession many, many times, but it was only recently that a particular phrase of it stood out to me, a phrase that briefly states an idea that I think is of enormous importance for the ideal of church unity. In describing the duties of the civil magistrate relating to religion, the Confession notes that it is the civil magistrate's duty "to take order, that unity and peace be preserved in the church." Particularly, I am now interested in the idea that part of the role of the civil magistrate is to help preserve "unity" in the church of Christ.
WHAT IS THE ESTABLISHMENT PRINCIPLE
How does the civil magistrate help preserve unity in the church of Christ? In order to answer this question, we need to look at the overall idea of civil government put forward by the Westminster Confession. The Confession puts forward a biblical view of the relationship between civil government and religion that has come to be known as the Establishment Principle. The Establishment Principle can be expressed in these two basic concepts:
1. The civil magistrate is not neutral in religious matters. This non-neutrality is both a logical necessity and a moral imperative. The civil magistrate is in the business of making and enforcing civil laws and public policies. In order to do this, he (or they--I'll use the singular pronoun for shorthand while recognizing the diversity of forms civil government can take) must have in mind ideals as to how society should function, a hierarchy of valuable ends that are worth pursuing, beliefs about what is right and wrong and good and bad, a perspective on what the purpose of civil government is and thus what tasks he should be about, and so on. But all of these ideals, beliefs, values, etc., are dependent upon which worldview is actually true. If Agnosticism or Atheism is the worldview through which we should view the world, this will lead to a particular set of ideals, values, and beliefs. If Islam is the correct worldview, this will lead to a quite different set of values and beliefs. If Reformed Christianity is true, this will lead to yet another distinct set of beliefs and values.
Granting that this is the case, it is evident to the mind of man, whether illuminated by special revelation or not, that civil governments ought to base their laws and policies not on falsehood but on reality. It would be absurd to hold that while it is good for individuals to base their lives on reality, it is perfectly reasonable and harmless for entire societies to be grounded in fundamentally false views about the nature of the universe. This is why Atheists and Agnostics are so bent on bringing about a fully secular society. A secular society is a society that assumes that we have no knowledge of the supernatural but only of the natural world. Secularists like to present secularism as a neutral point of view upon which government can be based, but of course it is not neutral at all--it is the political instantiation of Agnosticism or Atheism. How foolish, then, is it for Christians to advocate for a secular society! Can we imagine Atheists advocating for a Christian or an Islamic theocracy? Of course not. And yet we see Christians all too often advocating for an Agnostocracy or an Atheocracy (though they don't put it so bluntly).
Both Christian common-sense, then, as well as the Bible, leads us to conclude that the civil government should not be secular but should be explicitly, officially Christian. The civil magistrate should acknowledge and establish the true Christian religion and base his laws and policies on that truth. We see this idea put forward, among many other places in Scripture, in Romans 13:1-7:
Let every soul be subject unto the higher powers. For there is no power but of God: the powers that be are ordained of God. Whosoever therefore resisteth the power, resisteth the ordinance of God: and they that resist shall receive to themselves damnation. For rulers are not a terror to good works, but to the evil. Wilt thou then not be afraid of the power? do that which is good, and thou shalt have praise of the same: For he is the minister of God to thee for good. But if thou do that which is evil, be afraid; for he beareth not the sword in vain: for he is the minister of God, a revenger to execute wrath upon him that doeth evil. Wherefore ye must needs be subject, not only for wrath, but also for conscience sake. For for this cause pay ye tribute also: for they are God's ministers, attending continually upon this very thing. Render therefore to all their dues: tribute to whom tribute is due; custom to whom custom; fear to whom fear; honour to whom honour.The Westminster Confession summarizes this teaching in this way:
God, the supreme Lord and King of all the world, has ordained civil magistrates, to be, under Him, over the people, for His own glory, and the public good: and, to this end, has armed them with the power of the sword, for the defense and encouragement of them that are good, and for the punishment of evil doers. (WCF 23:1)
The civil magistrate is the "minister of God," whose job it is to keep the public sphere clear of evil and safe for the good as much as possible, judging good and bad and learning the rules and methods of his governing from the revelation of God.
Note also that these biblical principles do not lead to the conclusion that the civil magistrate should acknowledge and ground his laws in only some portion of God's revealed truth while neglecting other parts of it. The established religion should not be merely a lowest-common-denominator, watered-down form of Christianity, but it should embrace the fullness of the the whole counsel of God. Just as the individual, and the family, and the church, has no right to ignore any portion of God's Word, so the civil magistrate must also acknowledge all of it. The church ought not to be simply "Christian" in a lowest-common-denominator sort of way, but it should have a confession that is distinctly Reformed and Presbyterian (because the Reformed faith, summarized in the Westminster Standards, is the full and purest expression of biblical Christianity). Similarly, it is not just a watered-down Christianity that should be embraced by the civil magistrate and by the entire society, but true, biblical, Reformed Christianity.
2. The civil magistrate should not only acknowledge and establish the true religion in an abstract sense, but he should formally recognize the official rulers of the church. It is not enough for Christians and for churches to acknowledge some abstract concept of "proper biblical civil governance." We must fully and formally recognize the specific civil government that is set over us and the specific rulers who have formal rule over us in the civil sphere. To put it more specifically, as an American, I cannot simply acknowledge the abstract principles of biblical civil government; I must also formally acknowledge my allegiance to the particular civil government set over me by the providence of God--the federal government of the United States of America, the government of the State of Utah, and the government of the City of Orem. I must recognize and show proper respect and deference to all those who are formally recognized to have an official role in the functioning of these legitimate governments. If I do not like the current president of the United States, I cannot simply ignore him and decide to set up my own president. This would be rebellion against those who have lawful rule over me.
In the same way, the civil magistrate has an obligation not just to acknowledge in the abstract the doctrines of the true religion; he must also formally, explicitly, and officially recognize as established the true church of God. He must formally acknowledge and recognize the sessions, presbyteries, synods, and national assembly of the true church of Christ in his nation. He must recognize the formally-appointed officers who make up these ecclesiastical governing bodies.
The ideal the Establishment Principle points to is a situation where the society as a whole embraces a formal recognition of all of the leaders God has appointed over the people--both civil and ecclesiastical (and parental). The society of the United States of America, for example, ought to acknowledge both an official body of civil governance and an official body of ecclesiastical governance, which bodies mutually and formally acknowledge each other and support each other in their distinct spheres of jurisdiction and activity. Here in America, this concept is extremely foreign, as we have never had an officially-recognized established church. In Scotland, on the other hand, this situation is at least in principle familiar (if not currently functioning in the best of conditions, to put it mildly).
THE ESTABLISHMENT PRINCIPLE AND THE UNITY OF THE CHURCH
At this point we can begin to see how the Establishment Principle (EP) supports the unity of the church of Christ. We can see this partly by recognizing how societies that have abandoned (either explicitly or in practice) the EP and instead embraced a voluntaristic view of the relationship between church and state have correspondingly had trouble maintaining the unity of the church.
In the United States of America, for example, abandonment of the EP has gone hand in hand with abandonment of the concept of the formal unity of the church. This can be seen by taking a look at the revised version of the Westminster Confession embraced by the mainstream Presbyterian tradition in the United States, in particular the section on the civil magistrate that corresponds to the quotation from the original version of the Confession quoted at the very beginning of this article:
Civil magistrates may not assume to themselves the administration of the Word and sacraments; or the power of the keys of the kingdom of heaven; or, in the least, interfere in matters of faith. Yet, as nursing fathers, it is the duty of civil magistrates to protect the church of our common Lord, without giving the preference to any denomination of Christians above the rest, in such a manner that all ecclesiastical persons whatever shall enjoy the full, free, and unquestioned liberty of discharging every part of their sacred functions, without violence or danger. And, as Jesus Christ hath appointed a regular government and discipline in his church, no law of any commonwealth should interfere with, let, or hinder, the due exercise thereof, among the voluntary members of any denomination of Christians, according to their own profession and belief. It is the duty of civil magistrates to protect the person and good name of all their people, in such an effectual manner as that no person be suffered, either upon pretense of religion or of infidelity, to offer any indignity, violence, abuse, or injury to any other person whatsoever: and to take order, that all religious and ecclesiastical assemblies be held without molestation or disturbance (Westminster Confession 23:3 as revised by American Presbyterian synods in 1788).
Notice the intertwining here of two ideas, 1. that the civil magistrate ought not to establish or even show any favoritism to any particular Christian denomination, and 2. that there are multiple legitimate denominations. Historically, the embracing of denominationalism--the idea that there can be multiple, legitimate, de jure denominations--is what led to opposition to the EP. If there is more than one legitimate denomination, then it wouldn't make sense for the civil magistrate to establish only one of them. And yet the civil magistrate can't establish all of them, because they are not in full formal communion with each other and have contradictory teachings and practices. An attempt to formally recognize all of them fully would result in a contradictory position for the civil government. So the only solution was to disestablish them all and treat them all, in effect, as private organizations no different in principle from the Boy Scouts or a country club or any other purely voluntary, not-officially-recognized organization.
Disestablishmentarianism (that is, the abandonment of the principles of the EP) and denominationalism tend to reinforce each other in a society. Historically, in Britain and in the United States in particular, the pattern seems to have worked in this way: Before 1690, most Christians were opposed both to denominationalism and to disestablishmentarianism. They believed firmly that the church of Christ is one and that the nature of the church is incompatible with idea of multiple de jure denominations, and they also believed firmly that the state should formally acknowledge the legitimate denominational church. However, in 1690, toleration begin to be established in Britain. Multiple churches were allowed to exist without hindrance. This contributed more and more over time to the advancement of an agnostic attitude in British society, and people became more and more indifferent to the truth claims of the various churches. This attitude of indifferentism, in turn, created a lack of concern for the unity of the church. "Agreeing to disagree in a friendly and charitable manner" came to replace biblical unity as the ideal for the people of God. Toleration and indifferentism combined led to the setting up of more and more denominations until the point was reached that most of the church and the broader society became used to having multiple churches and thought nothing of it, even embracing it as the ideal--the state we are in today, except that we've now gone even further and embraced non-Protestant forms of Christianity and even non-Christian religions and Atheism and Agnosticism into the mix. Denominationalism and indifferentism, in turn, serve to reinforce the idea that the civil government should not establish a particular church, which then continues to reinforce denominationalism, which continues to reinforce disestablishmentarianism, and so on.
It is easy to see how an embracing of the EP would tend to be a scourge for denominationalism and would encourage concern for the formal unity of the church. We don't tend to have a problem similar to denominationalism in the civil sphere. That is, we don't live in societies where people go around joining themselves to a whole host of different civil magistrates based on their personal taste, agreeing happily to disagree: "Oh, David Cameron is your Prime Minister? That's nice! My personal Prime Minister is Ed Miliband!" This doesn't happen because we understand the concept that there is an officially recognized civil government. A person doesn't get to be a civil magistrate simply be standing up and declaring himself to be one. He has to be properly appointed and legitimately recognized. Otherwise, he is not legitimate, however much he may protest that he is or wish to be. Similarly, in the EP system, the church is formally recognized by the society. One cannot simply decide to start a new denomination and have it be recognized as legitimate. One has to go through the proper channels, and if one doesn't do so, one cannot be recognized as having any legitimate authority. If a session, or a presbytery, decides to break from the rest of the established church, the society will view that session or presbytery as having forfeited its legitimate authority to function and will treat it accordingly.
Thus, an EP way of looking at things, in contrast with voluntarism, will make it impossible for a situation to arise in which the legitimate church can come to be viewed as being made up of multiple independent denominations. Just as the fact that the federal government of the United States has an official position on who the legitimate governor of Utah actually is prevents multiple governors from being considered to be legitimate and accepted by different people in Utah, so the formal recognition of the true church by the civil government will have the effect of preventing multiple independent ecclesiastical organizations from being considered all to be legitimate, de jure churches (though it may still be recognized that those who are not members of the established, legitimate church may be, in fact, regenerated members of Christ's Body de facto or informally). The question of the de jure legitimacy and authority of the various existing denominations and the mandate of the unity of the church must be faced whether or not the civil magistrate does his part by formally recognizing and establishing Christianity and the church, but if he does do his part, it makes it much harder for the society to forget the importance of these principles and these questions and for the indifferentism that allows denominationalism to flourish to become established. In this way, the civil magistrate has a major role to play in taking order "that unity and peace be preserved in the Church."