After this Celsus continues: “If these (meaning the Christians) bring forward this person, and others, again, a different individual (as the Christ), while the common and ready cry of all parties is, 'Believe, if you will be saved, or else begone,' what shall those do who are in earnest about their salvation? Shall they cast the dice, in order to divine whither they may betake themselves, and whom they shall join?” Now we shall answer this objection in the following manner, as the clearness of the case impels us to do.
If it had been recorded that several individuals had appeared in human life as sons of God in the manner in which Jesus did, and if each of them had drawn a party of adherents to his side, so that, on account of the similarity of the profession (in the case of each individual) that he was the Son of God, he to whom his followers bore testimony to that effect was an object of dispute, there would have been ground for his saying, “If these bring forward this person, and others a different individual, while the common and ready cry of all parties is, 'Believe, if you will be saved, or else begone,'” and so on; whereas it has been proclaimed to the entire world that Jesus Christ is the only Son of God who visited the human race: for those who, like Celsus, have supposed that (the acts of Jesus) were a series of prodigies, and who for that reason wished to perform acts of the same kind, that they, too, might gain a similar mastery over the minds of men, were convicted of being utter nonentities. Such were Simon, the Magus of Samaria, and Dositheus, who was a native of the same place; since the former gave out that he was the power of God that is called great, and the latter that he was the Son of God. Now Simonians are found nowhere throughout the world; and yet, in order to gain over to himself many followers, Simon freed his disciples from the danger of death, which the Christians were taught to prefer, by teaching them to regard idolatry as a matter of indifference. But even at the beginning of their existence the followers of Simon were not exposed to persecution. For that wicked demon who was conspiring against the doctrine of Jesus, was well aware that none of his own maxims would be weakened by the teaching of Simon. The Dositheans, again, even in former times, did not rise to any eminence, and now they are completely extinguished, so that it is said their whole number does not amount to thirty. Judas of Galilee also, as Luke relates in the Acts of the Apostles, wished to call himself some great personage, as did Theudas before him; but as their doctrine was not of God, they were destroyed, and all who obeyed them were immediately dispersed. We do not, then, “cast the dice in order to divine whither we shall betake ourselves, and whom we shall join,” as if there were many claimants able to draw us after them by the profession of their having come down from God to visit the human race. On these points, however, we have said enough.
Source: Against Celsus (New Advent)