You may be wondering why we are discussing the origin of men when we set out to talk about the Word's becoming Man. The former subject is relevant to the latter for this reason: it was our sorry case that caused the Word to come down, our transgression that called out His love for us, so that He made haste to help us and to appear among us. It is we who were the cause of His taking human form, and for our salvation that in His great love He was both born and manifested in a human body. For God had made man thus (that is, as an embodied spirit), and had willed that he should remain in incorruption. But men, having turned from the contemplation of God to evil of their own devising, had come inevitably under the law of death. Instead of remaining in the state in which God had created them, they were in process of becoming corrupted entirely, and death had them completely under its dominion. For the transgression of the commandment was making them turn back again according to their nature; and as they had at the beginning come into being out of non-existence, so were they now on the way to returning, through corruption, to non-existence again. The presence and love of the Word had called them into being; inevitably, therefore when they lost the knowledge of God, they lost existence with it; for it is God alone Who exists, evil is non-being, the negation and antithesis of good. By nature, of course, man is mortal, since he was made from nothing; but he bears also the Likeness of Him Who is, and if he preserves that Likeness through constant contemplation, then his nature is deprived of its power and he remains incorrupt. So is it affirmed in Wisdom: "The keeping of His laws is the assurance of incorruption." And being incorrupt, he would be henceforth as God, as Holy Scripture says, "I have said, Ye are gods and sons of the Highest all of you: but ye die as men and fall as one of the princes."
St. Athanasius, On the Incarnation