The numerous oracles—fancied apparitions in sacred places, etc., dispelled by the sign of the Cross. The old gods prove to have been mere men. Magic is exposed. And whereas Philosophy could only persuade select and local cliques of Immortality, and goodness—men of little intellect have infused into the multitudes of the churches the principle of a supernatural life
And whereas formerly every place was full of the deceit of the oracles, and the oracles at Delphi and Dodona, and in Bœotia and Lycia and Libya and Egypt and those of the Cabiri, and the Pythoness, were held in repute by men's imagination, now, since Christ has begun to be preached everywhere, their madness also has ceased and there is none among them to divine any more. 2. And whereas formerly demons used to deceive men's fancy, occupying springs or rivers, trees or stones, and thus imposed upon the simple by their juggleries; now, after the divine visitation of the Word, their deception has ceased.
For by the Sign of the Cross, though a man but use it, he drives out their deceits. 3. And while formerly men held to be gods the Zeus and Cronos and Apollo and the heroes mentioned in the poets, and went astray in honouring them; now that the Saviour has appeared among men, those others have been exposed as mortal men, and Christ alone has been recognised among men as the true God, the Word of God. 4. And what is one to say of the magic esteemed among them? That before the Word sojourned among us this was strong and active among Egyptians, and Chaldees, and Indians, and inspired awe in those who saw it; but that by the presence of the Truth, and the Appearing of the Word, it also has been thoroughly confuted, and brought wholly to nought. 5.
But as to Gentile wisdom, and the sounding pretensions of the philosophers, I think none can need our argument, since the wonder is before the eyes of all, that while the wise among the Greeks had written so much, and were unable to persuade even a few from their own neighbourhood, concerning immortality and a virtuous life, Christ alone, by ordinary language, and by men not clever with the tongue, has throughout all the world persuaded whole churches full of men to despise death, and to mind the things of immortality; to overlook what is temporal and to turn their eyes to what is eternal; to think nothing of earthly glory and to strive only for the heavenly.
Source: On the Incarnation of the Word (New Advent)