He then goes on to rail against us after the manner of old wives. “You,” says he, “mock and revile the statues of our gods; but if you had reviled Bacchus or Hercules in person, you would not perhaps have done so with impunity. But those who crucified your God when present among men, suffered nothing for it, either at the time or during the whole of their lives. And what new thing has there happened since then to make us believe that he was not an impostor, but the Son of God?
And forsooth, he who sent his Son with certain instructions for mankind, allowed him to be thus cruelly treated, and his instructions to perish with him, without ever during all this long time showing the slightest concern. What father was ever so inhuman? Perhaps, indeed, you may say that he suffered so much, because it was his wish to bear what came to him. But it is open to those whom you maliciously revile, to adopt the same language, and say that they wish to be reviled, and therefore they bear it with patience; for it is best to deal equally with both sides—although these (gods) severely punish the scorner, so that he must either flee and hide himself, or be taken and perish.”
Now to these statements I would answer that we revile no one, for we believe that “revilers will not inherit the kingdom of God.” And we read, “Bless them that curse you; bless, and curse not;” also, “Being reviled, we bless.” And even although the abuse which we pour upon another may seem to have some excuse in the wrong which we have received from him, yet such abuse is not allowed by the word of God. And how much more ought we to abstain from reviling others, when we consider what a great folly it is!
And it is equally foolish to apply abusive language to stone or gold or silver, turned into what is supposed to be the form of God by those who have no knowledge of God. Accordingly, we throw ridicule not upon lifeless images, but upon those only who worship them. Moreover, if certain demons reside in certain images, and one of them passes for Bacchus, another for Hercules, we do not vilify them: for, on the one hand, it would be useless; and, on the other, it does not become one who is meek, and peaceful, and gentle in spirit, and who has learned that no one among men or demons is to be reviled, however wicked he may be.
Source: Against Celsus (New Advent)