Regarding the Incarnation doctrine, systematic theologian Owen Thomas writes:
"Now Middle Platonist philosophy involved a doctrine of God as impassible, completely transcendent and immutable. Thus on these terms it is extremely difficult to understand how God and humanity could be united in one person. But the fundamental thing we know from Christ is that God can be perfectly united with humanity. This is where we begin in speaking about God and humanity" (Thomas, Introduction to Theology, 150).
The doctrine of divine Impassibility (APAQEIA) was not only professed and believed by Neoplatonist philosophers: the early Church Fathers also uniformly affirmed God's impassible will and immutable nature. In the eyes of these Fathers, with the exception of the later Origen, God cannot suffer and he is completely immune to change. If what the Fathers posited were true, though, how could God and humanity ever be perfectly united in one hypostasis? How could a completely impassible God (actus purus) "become" flesh? It seems that He could not.
One Catholic gentleman tried addressing my question from the Latin perspective--but I felt that he did not reply to the primary issue raised by John 1:14. How could a God with no potential become anything whatsoever? In this regard, I find Owen Thomas' answer above somewhat interesting. His solution to the conundrum appears to be: "We cannot explain what happened in the Incarnation adequately, so we can only believe it." Or as Dietrich Bonhoeffer urged Trinitarians of his time: one should not try to prove that the Incarnation is true; to the contrary, one should only believe in the Incarnation. Similarly, a professor from the Lutheran seminary in Minnesota told me that the Incarnation "does not make sense." This position implies that the doctrine cannot be plumbed by logic, but must simply be believed and appropriated by faith, which is what Kierkegaard evidently professes.