top of page


Saint Irenaeus (130-202 AD) is an early Church saint who most people have probably not heard of but who was a crucially important figure as the early Church calcified what it believed and why.

He came from Izmir in modern day Turkey but ended up as bishop of Lyons in France. This information is significant for it posits Irenaeus as a bridge between Eastern and the Western Christianity. He was a friend of St Polycarp (69-155 AD) who was a disciple of the Apostle John. Therefore, Irenaeus was a close witness to the words and legacy of Jesus.

Irenaeus is remembered for his contribution to a major heresy that arose in the early Church. It was known as Gnosticism which taught that the world was created by a lesser divinity and that the spiritual or real world was made through Christ. This heresy created a split in how creation was perceived – the spiritual as good and the material as bad. It also created a split in the Church – between those who were smart enough to grasp this and those who were not. Irenaeus vigorously opposed this view and argued for the integrity of all creation in God – that everything was created by the one God and so was good. He also rejected the elitism of the gnostics and insisted that knowledge of God was open to everyone just as his love is the gift to all too. He emphasized the unity of the Old and New Testaments, Christ’s human and divine nature and the value of tradition. He also had a deep appreciation of the widespread presence and action of the Holy Spirit and connected this to the Church: ‘For where the Church is, there is the Spirit of God; and where the Spirit of God is, there is the Church and every kind of grace’.

For Irenaeus, the incarnation was the key moment of history when the Son of God became human and so God entered into history. God did this for love of us and in order to share the divine life with us his adopted family. Irenaeus described this in language of exchange: ‘For this is why the Word became man, and the Son of God became the Son of man: so that man, by entering into communion with the Word and thus receiving divine sonship, might become a son of God’. He also coined one of the most memorable statements of the early Church that sums up the interaction between God’s grace and human freedom. He wrote that ‘The glory of God is the human person fully alive’.

This means that God is not a competitor of humanity. God is not the enemy of our freedom but guarantees it. As Thomas Aquinas would later say, ‘God’s grace builds on nature’ and so illuminates the human person, making us more whole, beautiful and complete. Here is an argument that hasn’t gone away. Many are still convinced that we are better off without faith, without God. Better to go it alone. Irenaeus suffered martyrdom about the year 202, under the Emperor Severus, at Lyons.

Reflection of the life of St. Irenaeus

St. Irenaeus was a very gifted preacher. He had great patience in investigating the many controversies that were present in the period in which he lived. He had a great desire and a passion to get to the source of these controversies and heresies not because he wanted to prove others wrong but in order that he could shine God's light on it and reveal the truth to them. This approach that St. Irenaeus took reminds us that the discovery of truth is not to be a victory for some and a defeat for others but should be undertaken out of love and care for people so that all can rejoice and be a part of that victory. His famous words that the 'Glory of God is man fully alive' is a beautiful and powerful focus point of reflection for us all.

bottom of page