Had it been a case of one trespass only, and not of a subsequent corruption, repentance would have been well enough; but when once transgression had begun men came under the power of corruption proper to their nature and were bereft of the grace which belonged to them as creatures in the Image of God. No, repentance could not meet the case. What - or rather Who was it that was needed for such grace and such recall as we required? Who, save the Word of God Himself, Who also in the beginning had made all things out of nothing? His part it was, and His alone, both to bring again the corruptible to incorruption and to maintain for the Father His consistency of character with all. For He alone, being Word of the Father and above all, was in consequence both able to recreate all, and worthy to suffer on behalf of all and to be an ambassador for all with the Father.
-St. Athanasius, On The Incarnation