Celsus, then, does not speak as a good reasoner, when he compares the mortal flesh of Jesus to gold, and silver, and stone, asserting that the former is more liable to corruption than the latter. For, to speak correctly, that which is incorruptible is not more free from corruption than another thing which is incorruptible, nor that which is corruptible more liable to corruption than another corruptible thing. But, admitting that there are degrees of corruptibility, we can say in answer, that if it is possible for the matter which underlies all qualities to exchange some of them, how should it be impossible for the flesh of Jesus also to exchange qualities, and to become such as it was proper for a body to be which had its abode in the ether and the regions above it, and possessing no longer the infirmities belonging to the flesh, and those properties which Celsus terms “impurities,” and in so terming them, speaks unlike a philosopher?
For that which is properly impure, is so because of its wickedness. Now the nature of body is not impure; for in so far as it is bodily nature, it does not possess vice, which is the generative principle of impurity. But, as he had a suspicion of the answer which we would return, he says with respect to the change of the body of Jesus, “Well, after he has laid aside these qualities, he will be a God:” (and if so), why not rather Æsculapius, and Dionysus, and Hercules? To which we reply, “What great deed has Æsculapius, or Dionysus, or Hercules wrought?”
And what individuals will they be able to point out as having been improved in character, and made better by their words and lives, so that they may make good their claim to be gods? For let us peruse the many narratives regarding them, and see whether they were free from licentiousness or injustice, or folly, or cowardice. And if nothing of that kind be found in them, the argument of Celsus might have force, which places the forenamed individuals upon an equality with Jesus. But if it is certain that, although some things are reported of them as reputable, they are recorded, nevertheless, to have done innumerable things which are contrary to right reason, how could you any longer say, with any show of reason, that these men, on putting aside their mortal body, became gods rather than Jesus?
Source: Against Celsus (New Advent)