When beginning his discussion of the incarnation, St. Athanasius takes us all the way back to the beginning, the creation of the world. "The first fact that you must grasp," he writes with emphasis, "is this: the renewal of creation has been wrought by the Self-same Word Who made it in the beginning." All life comes from God, both physical and spiritual, therefore all death comes from that which is anti-God. So, the only way that life can be restored from death is through re-creation by the Creator. Through the will of God the Father, Christ, the eternal Word, works both to create us and to save us. Whatever the Word says is done; to speak something into existence is to make it; so also, to call us to repentance is to restore our spiritual life -- "...and those He called, He also justified..." (Rom. 8)
But before he gets to the significance of creation and new creation and their relationship to the incarnation, St. Athanasius delivers an interesting apologetic against false views of the creation event. In fact, although succinct, it is one of the best and most useful ever written, for these false ideas are still with us, surprisingly unchanged. We often think that in pre-modern times these false ideas were expressed in myths and stories, but St. Athanasius does not mentions these at all. He cites three prevailing philosophical viewpoints instead.
First, he cites the Epicureans, who said that "all things are self-originated, and, so to speak, haphazard" because they denied the existence of any kind of "Mind" behind the universe. This sounds, alarmingly like the theory of evolution, and philosophically, it is indeed the idea that stands behind naturalism. We even see here a hint of the scientific "random mutations over time." But St. Athanasius replies that they are not even paying attention to who they are or their own experience, for only one entity or thing could come of it, not the diversity we see all around us. (I have often felt that this logical argument against evolution is too little used. What would a random world really look like? It would be chaotic, no doubt, and lifeless, as well, completely without an ordering influence, and it could only, at best, produce one "thing." Yet, no system of operation or thought on the planet fundamentally works this way. We live in an ordered and complex world, even though we take it for granted.) The differences we see point to a designing Mind who employed engineering hands; in other words, a Cause. Consequently, any time one comprehends the cause of something so great as the universe, so vast as all things, it has to be God.
Second, he refers to Plato, who taught that God made everything from pre-existing, uncreated matter. This would make God out to be a craftsman like a carpenter, who makes items from already existing wood. This view puts limitations on God. He must work with something outside of himself, which he also did not have the power to create. If we understand God to be limitless and all-powerful, this type of creation could not be done by God at all; it would have to come about some other way. Plato's idea bears some resemblance to the steady-state theory of cosmology that maintained that the universe did not have a beginning but it has and will always exist in the same form as it is now perceived. Giving the universe some kind of eternal existence does away with the need for a cause, so any creator that might come along to make things must be less than God.
This brings us to the third theory, espoused by the Gnostics, who attributed creation to a demigod. They believed that God the Father appointed the task of creating to this lesser entity. However, St. Athanasius rather quickly points out that this goes completely against the teachings of Scripture, citing the passage in Mt. 19 that states that the same God who joins a man and a woman in marriage also created them. Another passage that supports creation by the triune God is Jn 1:1-3: "In in the beginning was the Word, and the Word was with God and the Word was God... All things were created through him..." Heb. 11:3 also tells us: "By faith we understand that the universe was created by God's command..." The Bible blatantly affirms that God, and no one or nothing else created the world. To argue against this in any way, he writes, is to be blind to the truth -- "These simply shut their eyes to the obvious meaning of Scripture."
In summary, St. Athanasius purposes three telling reasons why we should believe that God is the Creator of all things: 1.) There is strong evidence all around us for the existence of "Mind" -- design, order and unity of purpose exist in everything we observe, including ourselves. 2.) The generosity of God's goodness is evident in all that exists. God is good, therefore all he has made is intrinsically good and good for us. 3.) Humans bear in themselves a special grace or gift from God -- the very image of God, which enables us to think, feel and have the ability to know and be known by God.
Now, back to why this is central to the necessity for the incarnation. What was made so good and unblemished in the beginning, that is, the soul of man, was corrupted through mankind's conscience choice to sin against God. This brought about man's spiritual death and need for divine rescue. "It was our sorry case that caused the Word to come down, our transgression that called out his love for us..."
St. Athanasius believed that the Fall into sin, in a strange sort of way, negated the original creation. It placed man on a path towards non-existence, the road to Hell. Instead of being ever drawn towards Heaven, man was corrupted, turned irrevocably the other way. We were in danger passing away entirely, essentially returning back to nothingness, because evil had overtaken our hearts. Once this began to happen, "corruption ran riot," as the primal glory and purposes of creation were abandoned for the lusts and desires of fallen flesh. Only the presence of the eternal Word who had made humanity to begin with prevented its complete and utter obliteration.
It was sin, then, that has caused men, since almost the the very beginning of our existence, to lose sight of the truth about Creation. Sin made the heart of man blind to the purposes of the Creator and caused us to forget the glory and wonder from which we came. False theories about our origins have always plagued us, because we rebelled against the truth. So man has ever blindly followed a weary treacherous path of lies about the God from whom he came. But the amazing thing is, St. Athanasius affirms, it that God wanted us back so much that he expressed his creative love fully and finally by sending his Son to walk the dismal, dark and ruined human path: "...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."