Selections from "On the Incarnation" by Athanasius

God secured this grace that He had given by making it conditional from the first upon two things - namely, a law and a place. He set them in His own paradise, and laid upon them a single prohibition. If they guarded the grace and retained the loveliness of their original innocence, then the life of paradise should be theirs, without sorrow, pain or care, and after it the assurance of immortality in heaven. But if they went astray and became vile, throwing away their birthright of beauty, then they would come under the natural law of death and live no longer in paradise, but, dying outside of it, continue in death and in corruption...

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.

You know what happens when a portrait that has been painted on a panel becomes obliterated through external stains. The artist does not throw away the panel, but the subject of the portrait has to come and sit for it again, and then the likeness is re-drawn on the same material. Even so was it with the All-holy Son of God. He, the Image of the Father, came and dwelt in our midst, in order that He might renew mankind made after Himself.

Christ is the great hidden mystery, the blessed goal,
the purpose for which everything was created.
- St Maximus the Confessor