Against Celsus 1.7

Next, since he often calls our doctrine secret, here too he must be refuted, since almost the whole world knows the preaching of Christians better than the opinions of the philosophers. For who does not know of the birth of Jesus from a virgin, and of the crucified one, and of his resurrection, believed by many, and of the judgment that is proclaimed, which punishes sinners as they deserve and counts the righteous worthy of reward? Even the mystery of the resurrection, not being understood, is bandied about and laughed at by unbelievers. To say, then, that in view of all this the doctrine is secret is quite absurd. That there are certain things, as it were beyond the exoteric teachings, which do not reach the many, is not peculiar to the Christian teaching alone but belongs also to that of the philosophers, among whom some teachings were exoteric and others esoteric. Some heard Pythagoras only as "he himself said," while others were taught in secret the things not fit to reach profane ears not yet purified. And all the mysteries everywhere, in Greece and in the barbarian world, though secret, have not been slandered. So he slanders the secret element of Christianity in vain, without even understanding it accurately.