Pope Leo the Great
(Sermo 2 de Nativ. Domini)
GOD is He whose nature is goodness, whose will is power, and whose work is mercy.
Wherefore, at the very beginning of the world, as soon as the devil's hatred had mortally poisoned mankind with the venom on his envy, this almighty and merciful God even then foretold those remedies which his mercy had foreordained for our healing.
At that time he bade the serpent know that there was to be a seed of the woman who yet should crush the prideful swelling of his pestilential head. This seed was none other than the Christ to come in the flesh, even God and Man in one Person, who should be born of the Virgin, and by his virgin-birth should condemn the seducer of man.
THE devil rejoiced that he had, by his artful cunning, so deceived man as to make him lose the gifts of God, and forfeit the privilege of eternal life. Yea, when the devil had thus brought man under the hard sentence of death, he found a certain solace for his own misery in the fact that he now had a comrade in his guilt. He thought also that God, in His just anger, would change His original design towards man, whom he had made in such honor.
But, dearly beloved, that unchangeable God, whose will cannot be balked of its loving-kindness, in the dispensation of his own secret counsel, had already provided a mysterious way for carrying out his original purpose of goodness. So it was that mankind, which had been led into sin by the wicked craft of the devil, was not suffered to perish, and frustrate that gracious purpose of God.
Taken from an Anglican Breviary