To the Greeks, then, I have to say that the Magi, being on familiar terms with evil spirits, and invoking them for such purposes as their knowledge and wishes extend to, bring about such results only as do not appear to exceed the superhuman power and strength of the evil spirits, and of the spells which invoke them, to accomplish; but should some greater manifestation of divinity be made, then the powers of the evil spirits are overthrown, being unable to resist the light of divinity.
It is probable, therefore, that since at the birth of Jesus “a multitude of the heavenly host,” as Luke records, and as I believe, “praised God, saying, Glory to God in the highest, and on earth peace, good-will towards men,” the evil spirits on that account became feeble, and lost their strength, the falsity of their sorcery being manifested, and their power being broken; this overthrow being brought about not only by the angels having visited the terrestrial regions on account of the birth of Jesus, but also by the power of Jesus Himself, and His innate divinity.
The Magi, accordingly, wishing to produce the customary results, which formerly they used to perform by means of certain spells and sorceries, sought to know the reason of their failure, conjecturing the cause to be a great one; and beholding a divine sign in the heaven, they desired to learn its signification. I am therefore of opinion that, possessing as they did the prophecies of Balaam, which Moses also records, inasmuch as Balaam was celebrated for such predictions, and finding among them the prophecy about the star, and the words, “I shall show him to him, but not now; I deem him happy, although he will not be near,” they conjectured that the man whose appearance had been foretold along with that of the star, had actually come into the world; and having predetermined that he was superior in power to all demons, and to all common appearances and powers, they resolved to offer him homage.
They came, accordingly, to Judea, persuaded that some king had been born; but not knowing over what kingdom he was to reign, and being ignorant also of the place of his birth, bringing gifts, which they offered to him as one whose nature partook, if I may so speak, both of God and of a mortal man—gold, viz., as to a king; myrrh, as to one who was mortal; and incense, as to a God; and they brought these offerings after they had learned the place of His birth. But since He was a God, the Saviour of the human race, raised far above all those angels which minister to men, an angel rewarded the piety of the Magi for their worship of Him, by making known to them that they were not to go back to Herod, but to return to their own homes by another way.
Source: Against Celsus (New Advent)