According to Irenaeus (Haer. 3.4.1-2), the rule of faith is: "one God, the Creator of heaven and earth, and all things therein, by means of Christ Jesus, the Son of God; who, because of His surpassing love towards His creation, condescended to be born of the virgin, He Himself uniting man through Himself to God, and having suffered under Pontius Pilate, and rising again, and having been received up in splendour, shall come in glory, the Saviour of those who are saved, and the Judge of those who are judged, and sending into eternal fire those who transform the truth, and despise His Father and His advent." Strictly speaking, Irenaeus calls this the "ancient tradition" which he says even the illiterate Barbarians have accepted.
The regula fidei is a summary of Christian teaching in narrative form. P.M. Blowers ("The Regula Fidei and the Narrative Character of Early Christian Faith," Pro Ecclesia 6 [1997]: 208) writes: "The Great Church committed itself not to a universally invariable statement of faith but to variable local tellings of a particular story that aspired to universal significance." It may be the case, then, that the narrative of the regula fidei is itself birthed from the narrative of the biblical witness to the act of the triune God in Jesus Christ and this is what constitutes the unity of Scripture.
