One of the things that theologians have been discussing for centuries is the question of whether or not the incarnation would have happened anyway had mankind not fallen. Summed up, the question is incarnation anyway? The supralapsarians say yes, and the infralapsarians say no, with these terms not to be confounded with the same terms being used to describe the debate over the logical order of the decrees of God within the determinations of God. This, it seems to me, is like a college of lady bugs trying to discuss astrophysics.
In a similar way, the initial temptation regarding incarnation anyway? discussion is to say that this is a debate that we should not even be having—because the scriptural data for it would appear to be so sparse. But this is not a mere pointless counterfactual debate, or a trapeze act of high decretal theology.
It would seem that Paul’s teaching on the gift of the second Adam surpassing the transgression of the first Adam would require us to affirm, in some measure, a version of the felix culpa doctrine.
“But not as the offence, so also is the free gift. For if through the offence of one many be dead, much more the grace of God, and the gift by grace, which is by one man, Jesus Christ, hath abounded unto many.”
Romans 5:15 (KJV)
But to make the incarnation contingent upon Adam’s sin would seem to require a staggering, stupendous, gobsmackingly huge version of felix culpa—felix maxima culpa. This is because to say that absent sin there would not have been an incarnation is to say that absent sin there would not have been union with Christ. We would have continued on forever—unfallen and cheerful dufflepuds, but dufflepuds nonetheless. We would have been happy little putt putt creatures.
But now, because of the Fall, and because of God’s intervention through the person and work of Christ, we are given everlasting union with Christ? This makes the most stupendous gift we could possibly be given into a mere workaround, the result of divine troubleshooting. It does not see the creation of man has having had “union with Christ” in view from the beginning.
This, in its turn, affects our understanding of what the imago Dei means. If you take it, as I do, as the capacity for upgrade into union with Christ, a design feature not shared by the angels or other sentient beings, then we are left (in my view) with a reductionistic (and rationalistic) understanding of what it means to bear the image of God.