Irenaeus of Lyons · a new plain-English translation from the original language
The testimony of those who saw the Apostles concerning the preaching of the truth.
Such proofs being before us, then, there is no need to hunt elsewhere for a truth readily gotten from the Church, seeing that the Apostles, much like a wealthy man storing up his riches in a bank, deposited within her, in full abundance, everything belonging to the truth, so that anyone who desires may draw from her the water of life. She herself is the doorway into life; everyone else is a thief and a bandit. For this very reason we ought to steer clear of such people, and cherish with the greatest care whatever pertains to the Church, and grasp firmly the truth's own tradition. What then? Even if there were a dispute over some small question, would it not be right to turn to the most ancient churches, in which the Apostles lived, and to receive from them what is certain and clear regarding the present question? And what if the Apostles had not even left us the Scriptures — would it not then be needful to follow the sequence of the tradition which they passed along to those entrusted with running the churches? Many barbarian nations who believe in Christ give their assent to this very sequence, holding salvation written not with ink on paper but by the Spirit upon their hearts, and guarding the old tradition with great care — believing in a single God, fashioner of heaven and earth and of everything within them, through Christ Jesus, God's own Son, who, on account of his overwhelming love for what he had shaped, submitted to being born of the Virgin, joining humanity to God in his own person, and suffered beneath Pontius Pilate, and rose once more, and was taken up in glory, and will return in glory as deliverer of those granted salvation and as arbiter of those under judgment, casting into everlasting fire whoever twists the truth and holds his Father and his coming in contempt. Those who have believed this faith without letters are, as far as our language goes, barbarians; but as far as their opinions, customs, and manner of life go, they are, on account of their faith, most wise indeed, and pleasing to God, living in all righteousness, chastity, and wisdom. And should anyone announce to them what the heretics have concocted, addressing them in their native tongue, they would immediately clap their hands over their ears and run off as fast as they could, unwilling even to tolerate hearing such blasphemous nonsense. Thus, through that ancient tradition of the Apostles, they do not even admit into their thoughts any of the monstrous talk these people utter; for among them there has never been either assembly or doctrine founded on it.
For before Valentinus there were none who held the views of Valentinus; nor before Marcion did any hold the views of Marcion; nor, indeed, did any of the other malicious sects we have listed above exist before the founders and inventors of their perversity came into being. Valentinus came to Rome under Hyginus, grew in influence under Pius, and continued on into the time of Anicetus. Cerdon, who preceded Marcion, likewise came under Hyginus — who was the eighth bishop — often coming into the church and making confession; and so he went on, at one time teaching secretly, at another making confession, and at another being exposed by some for the evil things he taught, and being kept away from the assembly of religious men (Tertullian, Prescription against Heretics; Eusebius, Church History) — and this went on throughout that identical tenure of oversight. As for the remainder, those styled Gnostics, they took their beginnings, as we have shown, from Menander the disciple of Simon; and each of them appeared as father and champion of whatever opinion he had come to hold. All these, however, arose much later, in the very midst of the Church's own times, rising up into their own apostasy.