Packer: Biblical unity is not unity at any price

Continuing with my thoughts on Christian unity, here's a quote by the great JI Packer on when visible unity is not the thing to prize above all. He looks back to the Reformation as a time where it was right to break fellowship:

Where the gospel is, faith is, and where faith is, there the Church us, whatever institutions may be lacking; but no group or organisation can be acknowledged as the Church while it lacks the gospel. The Church becomes visible and identifiable, not by flaunting some historical pedigree of ministerial succession, but by professing and proclaiming the apostolic gospel by word and by sacrament.

On this basis the Reformers held, first, that their separation from Rome was no sin since Rome had effectively unchurched herself by corrupting the gospel; second, their separation was no breach of the Church's unity, since neither papal government and order, nor any other particular form, was essential to that unity; third, by recovering their own church-character through their renewed confession of the gospel the Reformed churches had actually recovered unity, and were now waiting for Rome itself to join their new-found fellowship.

[...] To separate for truth's sake, at the summons of a biblically enlightened conscience, is not sin. When, without failure of love or respect, men dissociate themselves from their previous church connections in order to be free to obey God, this is not, and never was, schism. It may be their duty - as the Reformers thought it their duty to break with Rome over the gospel, and as the Baptist and Independent dissenters of 1662 thought it their duty to stand apart from the re-established Church of England and gather churches according to what they held to be the biblical model.

For such separations the word 'schism' is a pejorative misnomer... It can only engender a false sense of guilt about divisions which are rooted in the cleavage of principle, and encourage an ungodly attitude of 'union at any price'. Union between separated churches in the same area is certainly to be sought ... but it may not be bought at the cost of truth, or the compromise of conviction.'

[The Doctrine and Expression of Christian Unity]

I guess it will come as no great surprise to many readers here that I believe along with Prof. Packer that there are times to break fellowship where the gospel is at stake. But what about in other situations? Are there other times in which it is right to break a form of fellowship? And how does this work in an inter-church partnership (or 'parachurch') situation like the ministry I am involved in? These are the questions I plan to turn to over coming days, with the help of other believers that have gone before us.

In his comment on my previous post, Chris highlights a more up-to-date expression of Prof. Packer's theology here, which considers questions of the contemporary 'Anglican realignment.'