This next section of Athanasius’ writing is complicated, but provides a vital component of his defense and explication of the Incarnation. I’ll do what I can to unravel it, but you made need to spend some time meditating on his words more than mine.
Athanasius considers the objection that since the Christian God is held to have created the world from nothing with a word (or Word as the case may be), he should have simply restored it with a command rather than through the messiness of the Incarnation. Athanasius responds that it requires more to cure that which already has existence than to bring it originally from non-existence.
To this objection of theirs a reasonable answer would be: that formerly, nothing being in existence at all, what was needed to make everything was a fiat and the bare will to do so. But when man had once been made, and necessity demanded a cure, not for things that were not, but for things that had come to be, it was naturally consequent that the Physician and Saviour should appear in what had come to be, in order also to cure the things that were. For this cause, then, He has become man, and used His body as a human instrument.
You see immediately that Athanasius primarily links Jesus’ saving work to the healing work of a physician, not in terms of law or judgment. Moreover, it required more to cure than it did to bring man into existence from nothing. I love this summary.
For it was not things without being that needed salvation, so that a bare command should suffice, but man, already in existence, was going to corruption and ruin.
Next comes another turn that bears close consideration.
Now if death were external to the body, it would be proper for life also to have been engendered externally to it. But if death was wound closely to the body and was ruling over it as though united to it, it was required that life also should be wound closely to the body, that so the body, by putting on life in its stead, should cast off corruption.
We’ve seen a lot about death and life in this treatise. Here he is drawing all of that together. Death and corruption had become part of the nature of man. We needed life. God had always been our only source of life and once we had abandoned life, the only way God could bring life to us was to become one of us — to assume our corrupted nature and destroy the death coursing through it.
For this cause the Saviour reasonably put on Him a body, in order that the body, becoming wound closely to the Life, should no longer, as mortal, abide in death, but, as having put on immortality, should thenceforth rise again and remain immortal. For, once it had put on corruption, it could not have risen again unless it had put on life. And death likewise could not, from its very nature, appear, save in the body. Therefore He put on a body, that He might find death in the body, and blot it out. For how could the Lord have been proved at all to be the Life, had He not quickened what was mortal?
Wow. Is that not a God worthy of not just all worship, but all love?
in this very way one may say, with regard to the body and death, that if death had been kept from the body by a mere command on His part, it would none the less have been mortal and corruptible, according to the nature of bodies; but, that this should not be, it put on the incorporeal Word of God, and thus no longer fears either death or corruption, for it has life as a garment, and corruption is done away in it.
All humanity has received life as a garment. It is no longer in the nature of man to die. We were meant to live.