Life
Irenaeus (c. 130–202), a disciple of Polycarp who became bishop of Lyon, wrote Against Heresies, a systematic refutation of the Gnostic sects then dividing Christians. He argued for the authority of the apostolic churches, the fourfold Gospel, and a unified account of salvation history, doing much to shape the emerging New Testament canon and orthodox theology. He is honored as one of the most important theologians of the second century.