Irenaeus

Irenaeus (c. 120 - 202) was bishop of Lyons, in what is now France, in the 2nd century. 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 Catholic Church considers him a Father of the Church[?]. He was a disciple of Polycarp, who himself was a disciple of John the Evangelist.

• Feast day: June 28

Irenaeus's magnum opus was Against Heresies (c. 185), where he argued that gnostics sects followed neither from logic, the Scriptures, nor the teachings of the Apostles. He was one of the first Christian writers to use the principle of apostolic succession to refute his opponents.

Irenaeus cited from most of New Testament canon, except that he also cited 1 Clement[?] and The Shepherd of Hermas. His writings do not refer toPhilemon, 2 Peter, 3 John and Jude. Irenaeus was the first Christian writers to list all four and exactly four of the now canonical gospels as divinely inspired, possibly in reaction to Marcion's edited version of Gospel of Luke, which he was touting as the one and only true gospel.

Until the discovery of the Library of Nag Hammadi in 1945, Against Heresies was the best description we had of gnosticism.

Irenaeus was the second bishop of Lyons. The first bishop was martyred during the persecutions under that philosopher-king Marcus Aurelius. Irenaeus happened to have been out of town at the time.

Irenaeus was a Greek from Polycarp's hometown of Smyrna, now in Turkey.

Irenaeus 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 Calvinist Huguenots. (The remains of Leonardo da Vinci and Kepler, among others, also were lost in the religious wars of those times).