But why need I disparagingly refer to strange spies and informers, when you allege against us such charges as we certainly do not ourselves divulge with very much noise—either as soon as you hear of them, if we previously show them to you, or after you have yourselves discovered them, if they are for the time concealed from you? For no doubt, when any desire initiation in the mysteries, their custom is first to go to the master or father of the sacred rites. Then he will say (to the applicant), You must bring an infant, as a guarantee for our rites, to be sacrificed, as well as some bread to be broken and dipped in his blood; you also want candles, and dogs tied together to upset them, and bits of meat to rouse the dogs. Moreover, a mother too, or a sister, is necessary for you. What, however, is to be said if you have neither? I suppose in that case you could not be a genuine Christian. Now, do let me ask you, Will such things, when reported by strangers, bear to be spread about (as charges against us)? It is impossible for such persons to understand proceedings in which they take no part. The first step of the process is perpetrated with artifice; our feasts and our marriages are invented and detailed by ignorant persons, who had never before heard about Christian mysteries. And though they afterwards cannot help acquiring some knowledge of them, it is even then as having to be administered by others whom they bring on the scene. Besides, how absurd is it that the profane know mysteries which the priest knows not! They keep them all to themselves, then, and take them for granted; and so these tragedies, (worse than those) of Thyestes or Œdipus, do not at all come forth to light, nor find their way to the public. Even more voracious bites take nothing away from the credit of such as are initiated, whether servants or masters. If, however, none of these allegations can be proved to be true, how incalculable must be esteemed the grandeur (of that religion) which is manifestly not overbalanced even by the burden of these vast atrocities! O ye heathen; who have and deserve our pity, behold, we set before you the promise which our sacred system offers. It guarantees eternal life to such as follow and observe it; on the other hand, it threatens with the eternal punishment of an unending fire those who are profane and hostile; while to both classes alike is preached a resurrection from the dead.
Tertullian
Ad Nationes, Book I
Chapter VII