Irenaeus

Born in Smyrna, Irenaeus grew up hearing Polycarp, who had himself known the apostle John — a living chain back to the eyewitnesses that he never tired of invoking. Migrating to Gaul, he became bishop of Lyons around 177, after persecution had claimed his predecessor. Against the bewildering systems of the Gnostics he set a simple architecture: one God, one Christ, one rule of faith handed down publicly in the churches. His Against Heresies is our richest window into second-century Christianity, and his vision of Christ 'recapitulating' Adam's story shaped all later theology.

As a boy he heard Polycarp of Smyrna, who had known the apostle John — a living link of only two steps back to the eyewitnesses.