An important early voice against the heresy of Gnosticism, Irenaeus’ writings are among the most important documents produced by the church fathers. He was influenced in his thoughts by St Polycarp, who himself had known some of the apostles and their immediate disciples.
Born in approximately 125 in or near Smyrna, a city on the Aegean Sea in what is now Turkey. He was raised in a Christian home, and may have heard Polycarp teach as young man. He became a priest in Lyon, eventually rising to the position of bishop, replacing the martyred Saint Pothinius.
His theological works, collectedas “Against the Heresies,” were originally written in Greek but quickly translated into Latin. This allowed for the works to be widely circulated, and are credited with dealing a death-blow to Gnosticism. He also wrote again Montanism and other debatable teachings of the age.
Details of the end of his life are scarce, as he seems to have thrown himself into his work as Bishop of Lyon. He is thought to have died in 202, of natural causes.