Irenaeus was a Christian of Greek descent, born 130 AD in Smyrna (Modern-day Izmir, Turkey.) He served as Bishop of Lugdunum in Gaul, now Lyon, France, and died there in 202 AD. A noted theologian, he was a disciple of Polycarp, who in turn was a disciple of John the Evangelist.
Remembered as the first great “systematic theologian”, Irenaeus combatted the heresies of his time, foremost of which was Gnosticism. In its simplest form, Gnosticism taught that humans are divine souls, trapped in the material world, the world having been made by an imperfect spirit. The root word Gnosis means “knowledge from experience.” To counter such false teachings, Irenaeus defined orthodoxy. He championed three pillars of orthodoxy: the scriptures, tradition inherited from the apostles, and the teaching of the apostles’ successors. He was one of the first to recognize all four gospels as equal and essential to the Christian life. His writings, first in Greek and then translated to Latin, were well circulated and succeeded in quelling the expansion of Gnosticism.
Irenaeus placed great emphasis on the unity of God and the unity of salvation history. He insisted that “in the beginning, God created…” and has been overseeing His creation ever since. God viewed humanity as immature creatures, requiring a long period of maturation, eventually growing into His divine likeness.
Saint Irenaeus explored the depths of Christian theology and epitomized the modern adage “The best defense is a good offense.” His preparation included in-depth studies of Christ as the New Adam, the life of Christ, apostolic authority, Paul’s Epistles, and the Millennium to name a few. But at the center of his theology are two indispensable truths: all that we encounter in life helps achieve spiritual maturity, and all unity and goodness are of God.