Here’s one advantage of established churches in which Parliament acts as a lay synod: you can have much less rigid church membership – one that, by demanding adherence only to catholic creeds, admits non-recusant papists and calls them into reformed worship – while also preserving confessional identity through an aristocracy of sorts (both of bishops and of MPs). The advantage seems to consist of big-tent reach and focused teaching.
Otherwise, you have a more democratic system in which church members cast votes in lots of important decisions. This arrangement you can resolve in two ways: either accept that many churches may, within a century or two, officially embrace heresy – as many Independent churches did in England, and as King’s Chapel in Boston became Unitarian without the approval of the bishops – through majority vote (or hope really hard, perhaps naïvely, that they won’t), or demand, like R. Scott Clark, that there be only one level of confessional subscription, one applied to both laity and ordained officers with equal rigour.[2, 3] The first approach contains the seeds of doctrinal and liturgical chaos; the hazards of the second approach are described by John Frame:
Clark has no response to the obvious objections to his proposal. Among those: (1) This kind of confessionalism limits the membership of the church to those well-enough educated to understand and intelligently affirm the treatise. This makes the door to Christ far narrower than Scripture does. This is, I think, a large part of the reason why Presbyterian and Reformed churches have largely been limited to the higher social and economic groups in society. (2) Young children are excluded from the church by this procedure, meaning that membership in the church is limited to those old enough to affirm the confession. (3) Those who want to join a church but who either fail to understand or have doubts about a few propositions will be strongly tempted to subscribe to the confession hypocritically. (4) This method of protecting the church leads the church to be preoccupied with the details of confessions and subscription, at the expense of the Bible itself. The present volume is a case in point.
I have, admittedly, exaggerated the risks of the first approach. If we take the Apostles’ Creed, the Nicene Creed and the Athanasian Creed (the last of which reflects the Definition of Chalcedon) as requirements of belief for church members, with all members presumed orthodox unless shown otherwise, those who wilfully and obstinately (i.e. not in mere ignorance) hold to positions contradicting the articles of these creeds can be expelled as heretics before their heresies have spread across the churches. There is, however, nothing in even this measure to serve as a formal check upon a church’s falling into the errors of Rome against the minister’s teaching – neither would we want to introduce cultish sociological practices just to keep congregations ‘in line’ doctrinally, any more than we’d fight pornography with prostitution. Though preaching and rightly administered church discipline can combat outright heresy, then, these alone cannot prevent an institutional slide toward other gospel-obscuring doctrines.
Useful for integrity
Though we Americans have chosen historically to disestablish churches on the individual state level and then to interpret the federal constitution as incompatible with church establishment on any level of government, I think establishment does deal with the problem of being catholic in right doctrine and catholic in breadth, like nothing else that I can think of. Practically, of course, I recognize that my lifetime’s unlikely to see established churches in the U.S., and that the Church before Constantine had other ways to maintain its catholic integrity, but this approach to the tension between confessional identity and inclusive posture seems to me to have no equal, though Presbyterian polity comes close.
A look at China suggests difficulties perhaps exceeding even those that faced the Church when Roman persecution had stopped. Like Rome in the days of persecution, China today suffers a proliferation of heresies, a proliferation even worse in that even a great synod won’t address it adequately. If individual choice is all there is, even an overnight disappearance of the heretical Witness Lee sect and the Eastern Lightning cult will leave major issues, issues of which many are blissfully unaware. Hearing of the problems festering beneath City Harvest Church (CHC) in Singapore, which no doubt are due to idolatrous Word-of-Faith and prosperity teaching (just look, the head pastor has a pop-star trophy wife!), I have misgivings about what the Charismatic churches, once freed from persecution, tend to become. Here’s a video that CHC made some months before coming under government investigation:
If you can stand watching the whole abomination, I commend your stomach for its strength. This is the vomit of theological chaos, which China seems to have in spades. I imagine that a renewed Christendom would be a useful way to clean up.
 Of course, the established church approach still doesn’t really deal with recusants like William Byrd, who was fined almost yearly for recusancy, but you can’t win ’em all. ↑
 In either system, confessional revision is possible, at least in principle. ↑
 One possible way to address this problem, which is to concoct an additional church document for members to subscribe to, is exactly the schismatical, disorderly kind of silliness we want to avoid: it has all the weaknesses of Clark’s approach, and more. At any rate, would you really want to excommunicate a church member for privately having Romanizing beliefs? I doubt it. ↑