Gregory of Nyssa — on Eph 4:8-9 (The Great Catechism, Chapter XXIII-XXIV)

“The Enemy, therefore, beholding in Him such power, saw also in Him an opportunity for an advance, in the exchange, upon the value of what he held. For this reason he chooses Him as a ransom for those who were shut up in the prison of death. But it was out of his power to look on the unclouded aspect of God; he must see in Him some portion of that fleshly nature which through sin he had so long held in bondage. Therefore it was that the Deity was invested with the flesh, in order, that is, to secure that he, by looking upon something congenial and kindred to himself, might have no fears in approaching that supereminent power; and might yet by perceiving that power, showing as it did, yet only gradually, more and more splendour in the miracles, deem what was seen an object of desire rather than of fear... His choosing to save man is a testimony of his goodness; His making the redemption of the captive a matter of exchange exhibits His justice, while the invention whereby He enabled the Enemy to apprehend that of which he was before incapable, is a manifestation of supreme wisdom... For since, as has been said before, it was not in the nature of the opposing power to come in contact with the undiluted presence of God, and to undergo His unclouded manifestation, therefore, in order to secure that the ransom in our behalf might be easily accepted by him who required it, the Deity was hidden under the veil of our nature, that so, as with ravenous fish, the hook of the Deity might be gulped down along with the bait of flesh, and thus, life being introduced into the house of death, and light shining in darkness, that which is diametrically opposed to light and life might vanish; for it is not in the nature of darkness to remain when light is present, or of death to exist when life is active.”