Irenaeus, << `ih` ree NEE uhs, >> Saint (A.D. 130?-202?), was one of the most important thinkers and leaders in the early Christian church. His thought also has influenced modern theologians (scholars who study God). In his principal work, Against Heresies, Irenaeus attacked Gnosticism, a religious movement that claimed secret knowledge about the nature of the universe and the origin and destiny of humanity (see Gnosticism ). In his book, Irenaeus asserted the authority of the Old Testament and of several writings that became part of the New Testament. Irenaeus argued for the authority of mainstream tradition in the church. He upheld the authority of bishops to decide what is true in matters of faith. Irenaeus also developed an important doctrine (teaching) called the “recapitulation of Christ,” which states that the progress of human salvation is summarized in, and sanctified by, the humanity of Jesus.
Irenaeus was born in Asia Minor. He went to Gaul (now mainly France), where he served as a priest. He was known as the peacemaker among conflicting church groups. About 177, he became bishop of Lugdunum (now Lyon, France). Irenaeus’s feast day is celebrated on June 28 in the Eastern Orthodox Churches and August 23 in the Roman Catholic Church.
