Irenaeus

Irenaeus was bishop of Lyons, in what is now France, in the second century A.D. He has been widely recognized as a saint by both the Eastern Orthodox Church and the Catholic Church, and his writings were formative in the early development of Christian theology. The Roman Church considers him a Father of the Church.

He was a disciple of Polycarp, who himself was a disciple of John the Evangelist.

• Born: 120 A.D.

• Died: 202 A.D.

Irenaeus's magnus opus was Against Heresies, where he examined the heresies of we would now call gnostics and showed how they followed neither from logic, the Bible nor the teachings of the Apostles. He was one of the first Christian writers to:

• Show that the God of the Old Testament and New Testament were the same god.

• Use the principle of apostolic succession to refute heretics

• List books that belong to the New Testament, the beginnings of a Christian canon.

Irenaeus's New Testament canon is the same as ours, but it had 1 Clement and The Shepherd of Hermas in place of Philemon, 2 Peter, 3 John and Jude.

Until the discovery of the Library of Nag Hammadi in 1945, Against Heresies was the best description we had of gnosticism. It turned out to be very accurate as Irenaeus wanted his fellow priests to know exactly what they were up against.

Irenaeus was the second bishop of Lyons. The first was martyred during the persecutions under that philosopher-king Marcus Aurelius.

Ireneaus was buried under the church of Saint John's in Lyons, which was later renamed St Irenaeus. His tomb and his remains were destroyed in 1562 by the Calvinists, who certainly didn't warm to notions of apostolic succession.