Mark Hausam's second post.
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."