I think this is a bit overstated, and might just beg the question: \”which confession\”? The doctrinal affirmations (or negations) of the church cannot be equated with some kind of progressive revelation. For example, the early creeds regarding the Trinity were products of their time, Greek philosophical answers to Greek philosophical questions. They state what cannot be said (that Jesus has anything else but two natures in one person). But the Scriptures have a far more robust doctrine of the Trinity than those early creeds. There is nothing, in my opinion, relevatory about them. They are fences. That\’s all.

Incidentally, if being a part of Reformed (scholastic) orthodoxy means taking the imputation of Christ’s active obedience as a sine qua non (something not clearly parsed in Scripture in that way), then count me out: the Reformed camp, thankfully, is big enough to not have to bend the knee to the Puritan exposition on Reformed theology.

[I]f the doctrine was not the sine qua non, it should have been. [...] Of course we must allow for the fact that the Holy Spirit leads the church into all truth, but not all at once!

I have been thinking along the same lines since your initial response.

The answer to question one is “yes.” Given that I think that the doctrine of the imputation of Christ’s active obedience to the believer in Spirit-wrought faith union with Christ is biblical, it is incumbent upon me to bring that truth to bear on my assessment of 17th century Reformed orthodoxy.

My answer to question two would be in two-parts. First, whether the doctrine was considered a sine qua non of Reformed Orthodoxy in the 17th century is a matter of examining the facts and assessing them. In other words, it is a factual question. So in this regard I am in agreement with the Richard Muller-Carl Trueman school of church history and historical theology. We must pay attention to what theologians said, not what we wish they had said. However, if the doctrine was not the sine qua non, it should have been. Here I may part company from the Muller-Trueman school. Of course we must allow for the fact that the Holy Spirit leads the church into all truth, but not all at once!

Given that I have not read all the germane Reformed theologians from the 17th century (although I have read many of them!) I would be reticent to pontificate on the factual question. On the question of whether the doctrine should have been a sine qua non, I have already given my assessment. This whole discussion relates to how we use and appropriate past theologians. While it is an interesting fact of history that Johannes Piscator, who first formulated the distinction between Christ’s passive and active obedience, did not believe that Christ’s active obedience was imputed to the believer, it is also a fact that the consensus of the Reformed church was that he was wrong. I share that viewpoint.

Really I think you are asking whether the fact that there was debate on this question at the Westminster Assembly should cause us to pause before we argue that the doctrine is a sine qua non of Reformed Orthodoxy now. I think not. I happen to be one who thinks the language makes best sense as affirming the doctrine. Do I wish that the stronger language had been retained or included? Sure. It may be that the later revision that John Owen had some part in, is a better form of words. However, I think the Westminster Standards are sufficient in affirming the doctrine.

I apologize for such a long response. But this is good.

While it is true that historically there has been development within Reformed theology, such that the topic was debated at the Westminster Assembly, we are past the point of turning back. Just as can’t pretend that the church didn’t formulate a doctrine of the Trinity or a doctrine of the two natures of Christ in one person, we can’t go back with regard to the doctrine of the imputation of the active obedience of Christ. Covenant theology would be emasculated otherwise. First of all, the active and passive obedience of Christ are not two obediences but two aspects of the whole of his one obedience. Secondly, whenever the imputation of Christ’s active obedience is denied it inevitably leads to some form of neonomianism where we are justified by our faith and imperfect obedience. Or to put it another way, we end up being justified by our sanctification. Jonathan Edwards would argue that such a view robs the Triune God of his glory in the whole matter of redemption.

I would have to agree.