The fact, therefore, that at the time appointed, according to the purpose of His will, Jesus Christ was crucified, dead, and buried was not the doom necessary to His own condition, but the method of redeeming us from captivity. For "the Word became flesh" in order that from the Virgin's womb He might take our suffering nature, and that what could not be inflicted on the Son of God might be inflicted on the Son of Man. For although at His very birth the signs of Godhead shone forth in Him, and the whole course of His bodily growth was full of wonders, yet had He truly assumed our weaknesses, and without share in sin had spared Himself no human frailty, that He might impart what was His to us and heal what was ours in Himself. For He, the Almighty Physician, had prepared a two-fold remedy for us in our misery, of which the one part consists of mystery and the other of example, that by the one Divine powers may be bestowed, by the other human weaknesses driven out. Because as God is the Author of our justification, so man is a debtor to pay Him devotion.
Leo, Sermon 67, on the Passion.