My first example today is from Loraine Boettner, who is a well-known Reformed theologian from the twentieth century and was a member of the Orthodox Presbyterian Church. I've not read a ton of what he has written, but I think his classic work, The Reformed Doctrine of Predestination, is fantastic. It is one of my favorite books, and it has been used to help many to come to a better understanding of the TULIP doctrines of the Reformed faith.
However, it appears that in matters of the nature of the church and church unity, Boettner's theology left much to be desired. Here is a selection from his book Roman Catholicism (Philadelphia: Presbyterian and Reformed, 1962, pp. 20-21):
In the Bible the word "church" never means a denomination. The Bible has nothing to say about denominations. Whether a local church choose to remain strictly independent, or to enter into a working agreement with one or more other local churches, and if so on what terms, is not discussed in Scripture, but is left entirely to the choice of the church itself. And we find that in actual practice churches range all the way from those that remain entirely unrelated to any other, to the other extreme of those that subject themselves to some hierarchy of denominational overlords who own the property and send the minister. . . .
When our Lord prayed for unity, "that they may all be one" (John 17:21), it was primarily a spiritual unity, a oneness of heart and faith, of love and obedience, of true believers, and only secondarily a unity of ecclesiastical organization, that He had in mind, as is made clear by the fact that He illustrated that unity by the relationship which exists between Himself and the Father--"even as thou, Father, art in me, and I in thee." Unity of faith must be achieved before there can be unity of organization. The ideal, of course, would be for the church to be one in both faith and organization. But it is clearly not yet ready for that. Much work remains to be done in teaching God's Word before that can be accomplished. As Christians become more closely united in doctrine they work together more harmoniously and want to be united more closely in organization. But unity of doctrine must always remain primary, for that relates to the very purpose for which the church was founded. The alleged tragedy of disunity of organization is more than offset by the real tragedy of disunity of doctrine that results when conservative and modernistic churches are combined in one organization. . . .
And after all perhaps the diversity of churches, with a healthy spirit of rivalry within proper limits, is one of God's ways of keeping the stream of Christianity from becoming stagnant. History is quite clear in showing that where there has been enforced uniformity the church has stagnated, whether in Italy, Spain, France, or Latin America. The confinement of religious life to a dead level of uniformity does not solve our problems.
This is no less than a blatant abandonment of presbyterian ideas regarding the nature and unity of the church for an explicit semi-congregationalism, at least in the first and third paragraphs. The second paragraph seems to affirm that churches ought to work towards organizational unity, but he contradicts this sentiment in both the first and the third paragraphs where he asserts that there is no real biblical reason to have catholic organizational unity. Even in his second paragraph, he seems to lean towards the "Yeah, that's the ideal but it's not realistic right now" kind of attitude that makes many theoretical presbyterians feel comfortable ignoring the implications of denominational division. (I've discussed this here and here.)
My other example of the day comes from an anonymous correspondent, a pastor in a conservative American Presbyterian denomination. This statement was made in the context of a discussion over what the Bible requires regarding homeschooling:
So, many of these things come down to one's conscience before God and His Word. Prayerfully, they are in a church community that will help them answer those questions and will show love even if they disagree. This is why we have different churches and different denominations (pluralformity) because we all have different beliefs of what is right or wrong according to our informed consciences. That is why Paul does not offer details in many questions but emphasizes love, patience, longsuffering, gentleness, against which there is no law.
Ugh! These comments show how the sort of indifferentism which has come to full flower in our modern Agnostic western culture and is here manifested at a much weaker level contributes towards the abandonment of the historic Reformed presbyterian view of the unity of the church. "We can't have just one catholic visible church! Why, people have different opinions that must be respected! It's not like there's one Bible we've been given which teaches one set of truths that we are all obligated to believe and practice whether we like it or not! Oh wait . . ."
Despite the opinions of Boettner and my anonymous correspondent, the Bible and the Westminster Standards are quite clear that there is to be one catholic visible church, that unity between de jure churches in a single, overarching presbyterian structure is not an optional thing, that agreement in the truth is a good thing and diversity in belief over things the Bible teaches is bad, and that denominational division is not simply a convenient way of doing church but is a manifestation of sinful schism in the Body of Christ. See here, here, and here for more on these things, and see here for evidence that the Orthodox Presbyterian Church, despite the semi-congregationalism of some of her members and ministers, officially embraces a more biblical presbyterianism.