Tertullian, Prescription against Heretics 21

So we lay down our rule: if the Lord Jesus Christ sent the Apostles to preach, then no other preachers are to be accepted except the ones Christ himself appointed. For no one knows the Father except the Son, and those to whom the Son chooses to reveal him. And the Son does not appear to have revealed the Father to anyone except the Apostles he sent to preach — precisely what he revealed to them. Now, what they preached — that is, what Christ revealed to them — I insist must be proved in no other way than through the very churches the Apostles themselves founded, preaching to them in person, as they say, with living voice, and later by their letters. If that is how it stands, then it follows that any doctrine which agrees with those apostolic churches — the matrices and originals of the faith — is to be counted as true, beyond doubt holding what the Churches received from the Apostles, the Apostles from Christ, Christ from God. But every other doctrine is to be prejudged as a lie, if it clashes with the truth of the Churches, the Apostles, Christ, and God. It remains, then, for us to demonstrate whether our own doctrine, whose rule we published above, is reckoned to come from the tradition of the Apostles — and by that very fact, whether the rest come from a lie. We are in communion with the apostolic churches, because our doctrine differs in no respect: this is the testimony of the truth.