St. Irenaeus of Lyons

On the life, writings and spirituality of St. Irenaeus of Lyons, bishop and martyr

St. Irenaeus of Lyons, c. 130-202 A.D.: considered the 1st great theologian of the Church

Biographical sketch

The name of Irenaeus means in Greek "peace lover" or "peacemaker". He was born probably in Asia Minor about the year 130 A.D. He became a priest in early adulthood in the year 177 A.D. at Lyons in France and afterwards was made bishop of that city. Known as a disciple of St. Polycarp, bishop of Smyrna, he was sent to work under Pothinus, the bishop of Lyons, to evangelize the Gauls. It was at this time that Montanus spread erroneous interpretations of Sacred Scripture. Pothinus thus sent Irenaeus to Rome to plead with the Pope for leniency to Montanus and followers. But persecutions of Christians had begun in Gaul. During the absence of St. Irenaeus, Pothinus and others were martyred, and when Irenaeus returned, it was to replace Pothinus as bishop.

St. Irenaeus of Lyons proved himself an excellent pastor, and he was indeed true to his name because he served as moderator of many disputes. In 190 A.D., he restored peace between Pope Victor III and the Christians in Asia Minor, who were excommunicated for observing Easter on the date of Jewish Passover.

St. Irenaeus defended the Catholic faith in his books and soon died a martyr in 202 A.D. during the persecution of Christians under Septimus Severus.

Teaching and spirituality

St. Irenaeus wrote to defend the Catholic faith against the errors of the Gnostics, particularly Valentinian Gnosticism. Valentinian Gnosticism was a popular 2nd century movement which sees God as unknowable and totally remote from matter. However, St. Irenaeus rejects the Gnostic claim that this unknowable God is hostile to the material world. He defended the Catholic faith from this wrong teaching by showing that God is like a loving parent from whom all humanity receives the breath of life. St. Irenaeus teaches that although God may be transcendent and unknowable, God is also immanent - He can be known in love. His basic principle: God cannot be comprehended according to greatness, but only according to love. And according to St. Irenaeus, God's glory is the human person fully alive. The glory of God's divine presence can thus be seen in the dynamism of our human life.

Books and writings

St. Irenaeus wrote the books, "Against Heresies" and "The Proof of the Apostolic Preaching"


Listed below are excerpts from his writings. We can learn about the teaching of St. Irenaeus through what he wrote to defend the Catholic faith.


God shaped the first human; it was God - and no lesser being - who breathed the breath of life into the face of that first human being and imprinted the divine image in its very flesh (Against Heresies 5,6,1)

The glory of God is the living human person, and the life of the human person is the vision of God (Against Heresies 4,20,7)


The joining of the flesh made in the image of God and the soul forms the whole person made into the likeness by the Spirit (Against Heresies 5,6,1)