It seems that many, if not most, of Jenson’s most shocking innovations fall neatly into place once we recognize his debt to Barth, especially Barth’s doctrine of election. To wit:
Election is God’s self-determination. It is not only a determination of the future of the world and humans, but of God’s own involvement with that world and those humans. By election, the triune God determines Himself to be God in a particular way in this particular creation.
For Barth, what God decides, God is. The God He determines to be is not a mask hiding a God who has determined to be otherwise. When God determines to be God-for-us, by that very decision He is just that.
In fact, God has determined to be involved in time and history, not to be immune from it. Since His determination is His being, He is the God involved in time and history.
In fact, God has determined to be the Father who sent the Son to take flesh as Jesus, die and rise, so that He might send the Spirit. This gospel narrative is no mask for a God undetermined by the gospel. And because God determined Himself to be God in this world according to the gospel story, that is precisely who and what He is. Thus is God identified not only by but with the events of the gospel.
Always, Jenson qualifies with an “it might have been different if God had decided otherwise,” but then just as regularly adds that this difference is not something we can possibly know. What we know is how God determined Himself to be God in this world, and we know that this self-determination is the gospel.