Bruce McCormack gives an analysis here of Westminster’s response to Peter Enns. In a nutshell, McCormack argues that WTS gives a Lutheran or Eastern Orthodox reading of Chalcedon, which leads directly to theosis as an appropriate soteriology. He clearly doesn’t think that’s appropriate for Reformed theology. Here’s an interesting quote (especially the last part):
I have to say that this is the last thing I expected to discover in a report issued by Westminster Seminary theologians. I live in an ecclesial world in which those who value Christian orthodoxy as a concept seem invariably to drift towards either Rome or Constantinople or some amalgamation of the two which is represented by no existing church. The last thing most of my friends want is a truly Protestant theology (whether Lutheran or Reformed); theosis is the hot topic in soteriology and both Lutheran and Reformed theologians are struggling mightily to find something akin to a theosis doctrine in their own church fathers (in Luther but also in Calvin – as Todd Billings’ recent book amply demonstrates). Mind you, I am not accusing the theologians of Westminster of abandoning Reformed soteriology! But they do not seem to realize that in advocating the version of Chalcedonian Christology they do, unreconstructed by Reformed sources, they have taken a most important step in that direction. After all, which soteriology do they think the Chalcedonian Definition was originally designed to support?
He indicates that the framers of Chalcedon would only have assumed theosis and that only later interpretations have corrected this original errant position. I would agree with the former, but question the latter.