The deliberations and debates of the holy fathers with heresies are of no small moment. Why, for example, was it of such great necessity to refute Arius at Nicaea, Evtikios at Chalcedon, and Nestorius at Ephesus?

They were defending the very nature of redemption in all these cases, the purpose and nature of the Incarnation itself. When Athanasios says that "God became man so that man may become God," this is no trite statement. The crucifixion and resurrection of Christ would have very little meaning without the Incarnation.

The purpose of the incarnation was to bring to an end the alienation between the divine nature and the human nature and make Theosis the destiny of man. This could be accomplished only if Christ had taken on the fullness of the human nature, and not a portion of it only. In Himself, he brought the human nature – the fullness of the human nature –  into unity, into participation in the divine nature so that, as apostle Peter says in his epistle, we might receive the great and glorious, “exceeding great and precious promises: that by these ye might be partakers of the divine nature.” (2 Peter 1:4)
     

This is why we say in the prayer, "he took our human nature upon his shoulders and bore it to the cross." Without this understanding, one could still centuries later the wondering and questioning, "Cur deus homo” and come to the monstrous conclusion that the purpose of the incarnation was to constitute a fit human sacrifice capable of assuaging God and fulfilling His "justice."

Ransoming our human nature from bondage to the fear of death, or in the words of Saint Basil the Great in his great Eucharistic prayer, "he ransomed us from the grave." Since man was held in bondage through the fear of death to the one who had the power of death, namely Satan, being ransomed from the fear of death was at the same time redemption from servitude to Satan. Christ took on the fullness of our human nature, ended its alienation from the Divine nature, and bore our human nature to the cross, ransoming it from death, thus redeeming us from bondage to Satan; a bondage into which we had fallen, being sold through sin into that bondage.

One of the problems appears to be thinking that sin is the problem rather than a symptom of the problem. The problem is our alienation from God since the mark or goal which we fall short of (`amartia) is participation in the divine nature – it isTheosis.

The holy fathers, perhaps none more than Gregory of Nyssa, call us to Christian theoria; to a new contemplation, not of the world or even just of life, but a contemplation of “being” itself. The theoria of the philosophers could result in epiphanies, but Christian theoria leads to theophany, not a mere epiphany.

Einstein relates that when he was trying to think of a way to formulate relativity while hiking alone in the mountains. He had an "epiphany" about how to formulate it. When Archimedes lept naked from the bathtub and ran shouting “Eureka,” he had experienced an epiphany. Christian theoria leads, not to an epiphany, but to theophany. Saint Gregory calls us to Christian theoria – a new contemplation of "being." And Saint Maximos would agree: we have "received" only when we have "contemplated."