Athanasius and the Incarnation
In his seminal work, On the Incarnation, St. Athanasius of Alexandria presents the incarnation of Christ as the decisive act of God in human history. The act of God taking on human flesh integrates both his works of creation and his works of redemption.
Drawing on the words of the Apostle John, Athanasius identifies Christ as the source of all goodness in creation. "For God is good, or rather the source of all goodness, and one who is good grudges nothing, so that grudging nothing its existence, he made all things through his own Word, our Lord Jesus Christ. Among these things, of all things upon earth he had mercy upon the human race, and seeing that by the principle of its own coming into being it would not be able to endure eternally, he granted them a further gift, creating human beings not simply like all the irrational animals upon the earth but making them according to his own image, giving them a share of the power of his own Word, so that having as it were shadows of the Word and being made rational, they might be able to abide in blessedness, living the true life which is really that of the holy ones in paradise." 
Starting with the assumption that the Creator is the source of all goodness in creation, Athanasius does not identify the problem of sin and the fall with the existence of material creation, as the Gnostics did, but with humanity’s own turning away from the source of all goodness. Sin is then a disposition towards that which humanity was created from, a disposition to nothing. “For the transgression of the commandment returned them to the natural state, so that, just as they, not being, came to be, so also they might rightly endure in time the corruption unto non-being.” 
Since sin turns humankind to its natural state of non-being, the natural result of the transgression is death. “By the law death thereafter prevailed against us, and it was impossible to escape the law, since this had been established by God on account of the transgression.”  Sin introduced the principal of death, an undoing of creation. God’s redemptive work would then have to deal with both sin and death in an effort to restore creation and redirect humanity back towards the source of all goodness.
Against the Arians, Athanasius saw it as impossible for a mere human to perform this grand act of redemption, but must be accomplished by God alone. “Being the Word of the Father and above all, he alone consequently was both able to recreate the universe and was worthy to suffer on behalf of all and to intercede for all before the Father.”  By taking on a human body, Christ was able to encounter death and, as God, come through the trial as the victor. "And thus, taking from ours that which is like, since all were liable to the corruption of death, delivering it over to death on behalf of all, he offered it to the Father, doing this in his love for human beings, so that, on the one hand, with all dying in him the law concerning corruption in human beings might be undone (its power being fully expended in the lordly body and no longer having any ground against similar human beings), and, on the other hand, that as human beings had turned towards corruption he might turn them again to incorruptibility and give them life from death, by making the body his own and by the grace of the resurrection banishing death from them as straw from the fire….Coming himself into our realm, and dwelling in a body like the others, every design of the enemy against human beings has henceforth ceased, and the corruption of death, which had prevailed formerly against them, perished." 
Not only was the incarnation necessary to destroy the powers of death, it also served to reveal God to humanity so that humankind could once again look towards their Creator. "For in both ways the Savior exercised his love for human beings through his incarnation, in that he both banished death from us and renewed us, and also in that, although being unseen and invisible, through his works he appeared and made himself known to be the Word of the Father, the ruler and king of the universe." 
Because of the work of Christ in his incarnation, all peoples can see their Creator in whose image they were made, and in his death and resurrection, they are freed from the power of sin and death and made able to experience the resurrection life of the Redeemer.
 St. Athanasius of Alexandria, Inc. 3
 Ibid. 4
 Ibid. 6
 Ibid. 7
 Ibid. 8-9
 Ibid. 16