Jesus, accordingly, in turning away the minds of His disciples, not merely from giving heed to sorcerers in general, and those who profess in any other manner to work miracles— for His disciples did not need to be so warned— but from such as gave themselves out as the Christ of God, and who tried by certain apparent miracles to gain over to them the disciples of Jesus, said in a certain passage: “Then, if any man shall say unto you, Lo, here is Christ, or there; believe it not. For there shall arise false Christs, and false prophets, and shall show great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect. Behold, I have told you before. Wherefore, if they shall say unto you, Behold, he is in the desert, go not forth; behold, he is in the secret chambers, believe it not. For as the lightning comes out of the east, and shines even to the west, so also shall the coming of the Son of man be.” And in another passage: “Many will say unto Me in that day, Lord, Lord, have we not eaten and drunk in Your name, and by Your name have cast out demons, and done many wonderful works? And then will I say unto them, Depart from Me, because you are workers of iniquity.” But Celsus, wishing to assimilate the miracles of Jesus to the works of human sorcery, says in express terms as follows: “O light and truth! He distinctly declares, with his own voice, as you yourselves have recorded, that there will come to you even others, employing miracles of a similar kind, who are wicked men, and sorcerers; and he calls him who makes use of such devices, one Satan. So that Jesus himself does not deny that these works at least are not at all divine, but are the acts of wicked men; and being compelled by the force of truth, he at the same time not only laid open the doings of others, but convicted himself of the same acts. Is it not, then, a miserable inference, to conclude from the same works that the one is God and the other sorcerers? Why ought the others, because of these acts, to be accounted wicked rather than this man, seeing they have him as their witness against himself? For he has himself acknowledged that these are not the works of a divine nature, but the inventions of certain deceivers, and of thoroughly wicked men.” Observe, now, whether Celsus is not clearly convicted of slandering the Gospel by such statements, since what Jesus says regarding those who are to work signs and wonders is different from what this Jew of Celsus alleges it to be. For if Jesus had simply told His disciples to be on their guard against those who professed to work miracles, without declaring what they would give themselves out to be, then perhaps there would have been some ground for his suspicion. But since those against whom Jesus would have us to be on our guard give themselves out as the Christ— which is not a claim put forth by sorcerers— and since He says that even some who lead wicked lives will perform miracles in the name of Jesus, and expel demons out of men, sorcery in the case of these individuals, or any suspicion of such, is rather, if we may so speak, altogether banished, and the divinity of Christ established, as well as the divine mission of His disciples; seeing that it is possible that one who makes use of His name, and who is wrought upon by some power, in some way unknown, to make the pretence that he is the Christ, should seem to perform miracles like those of Jesus, while others through His name should do works resembling those of His genuine disciples.
Paul, moreover, in the second Epistle to the Thessalonians, shows in what manner there will one day be revealed “the man of sin, the son of perdition, who opposes and exalts himself above all that is called God, or that is worshipped; so that he sits in the temple of God, showing himself that he is God.” And again he says to the Thessalonians: “And now you know what withholds that he might be revealed in his time. For the mystery of iniquity does already work: only he who now lets will let, until he be taken out of the way: and then shall that Wicked be revealed, whom the Lord will consume with the spirit of His mouth, and shall destroy with the brightness of His coming: even him, whose cunning is after the working of Satan, with all power, and signs, and lying wonders, and with all deceivableness of unrighteousness in them that perish.” And in assigning the reason why the man of sin is permitted to continue in existence, he says: “Because they received not the love of the truth, that they might be saved. And for this cause God shall send them strong delusion, that they should believe a lie; that they all might be damned who believed not the truth, but had pleasure in unrighteousness.” Let any one now say whether any of the statements in the Gospel, or in the writings of the apostle, could give occasion for the suspicion that there is therein contained any prediction of sorcery. Any one, moreover, who likes may find the prophecy in Daniel respecting antichrist. But Celsus falsities the words of Jesus, since He did not say that others would come working similar miracles to Himself, but who are wicked men and sorcerers, although Celsus asserts that He uttered such words. For as the power of the Egyptian magicians was not similar to the divinely-bestowed grace of Moses, but the issue clearly proved that the acts of the former were the effect of magic, while those of Moses were wrought by divine power; so the proceedings of the antichrists, and of those who feign that they can work miracles as being the disciples of Christ, are said to be lying signs and wonders, prevailing with all deceivableness of unrighteousness among them that perish; whereas the works of Christ and His disciples had for their fruit, not deceit, but the salvation of human souls. And who would rationally maintain that an improved moral life, which daily lessened the number of a man's offenses, could proceed from a system of deceit?
Source: Against Celsus (New Advent)