12 You go on to quote Christ's words, that all who came before Him were thieves and robbers. How do you know that these were Christ's words, but from the Gospel? You profess faith in these words, as if you had heard them from the mouth of the Lord Himself. But if any one declares the verse to be spurious, and denies that Christ said this, you will have, in reply, to exert yourself in vindication of the authority of the Gospel. Unhappy being! What you refuse to believe is written in the same place as that which you quote as spoken by the Lord Himself.
We believe both, for we believe the sacred narrative in which both are contained. We believe both that Moses wrote of Christ, and that all that came before Christ were thieves and robbers. By their coming He means their not being sent. Those who were sent, as Moses and the holy prophets, came not before Him, but with Him. They did not proudly wish to precede Him, but were the humble bearers of the message which He uttered by them. According to the meaning which you give to the Lord's words, it is plain that with you there can be no prophets.
And so you have made a Christ for yourselves who should prophesy a Christ to come. If you have any prophets of your own, they will have, of course, no authority, as not being recognized by any others; but if there are any that you dare to quote as prophesying that Christ would come in an unreal body, and would suffer an unreal death, and would show to His doubting disciples unreal marks of wounds, not to speak of the abominable nature of such prophecies, and of the evident untruthfulness of those who commend falsehood in Christ, by your own interpretation those prophets must have been thieves and robbers, for they could not have spoken of Christ as coming in any manner unless they had come before Him.
If by those who came before Christ we understand those who would not come with Him—that is, with the Word of God—but without being sent by God brought their own falsehoods to men, you yourselves, although you are born in this world after the death and the resurrection of Christ, are thieves and robbers. For, without waiting for His illumination that you might preach His truth, you have come before Him to preach up your own deceits.
Source: Reply to Faustus the Manichaean (New Advent)