Irenaeus of Lyon declared Doctor Unitatis

On Friday, January 21, Pope Francis officially declared Saint Irenaeus of Lyon the 37th Doctor of the Church with the title Doctor unitatis.

Wolfymoza, CC BY-SA 4.0, via Wikimedia Commons

In his decree, the Pope wrote, “Saint Irenaeus of Lyon, who came from the East, exercised his episcopal ministry in the West: he was a spiritual and theological bridge between Eastern and Western Christians. His name, Irenaeus, expresses that peace which comes from the Lord and which reconciles, restoring unity. May the teaching of this great Master increasingly encourage the journey of all the Lord’s disciples towards full communion.”

St. Irenaeus, Bishop of what is now Lyon in the late 2nd century, was an example of ecumenical bridge-building in theology and practice. His best-known work, Against Heresies, refuted the Gnostics by defending the centrality of the Incarnation of Christ in human flesh as instrumental for human salvation and for humanity’s eventual incorporation into the Divine.

For Irenaeus, the salvific act of the fullness of Jesus’ Incarnation (birth, life, death, and resurrection) did not merely restore humans to what they were before the fall of Adam and Eve- it actually improved their situation by giving them divine potential. This infusion of divinity moved humanity’s relationship with God to a completely different level: humanity is now capax dei, capable of being part of the divine, capable of experiencing the love God has for them in a new and more profound way.

Irenaeus suggested that this new, more-than-restored, recapitulated reality for humanity is the culmination of what was intended in creation. Adam and Eve were not the perfect picture of humanity’s potential, but an immature, not-fully-developed version of what people could eventually become. Because of the fall, a natural outcome of free will, and the intervention by God in the Incarnation, people are recapacitated to have a fuller relationship with God than they ever had before. Irenaeus shows us a loving God in pursuit of God’s people, a God who from the beginning brought them out of nothing so that they could eventually be incorporated into God.

As a theology student and a person who straddles multiple Christian denominations, I’ve been entangled in my share of ecumenical conversations on salvation that wade into the issues of free will and God’s motives in creation and redemption and get stuck there. Irenaeus gives us a way to frame the issue of free will and the question of the divine dilemma that is filled to the brim with divine love. God, in creating humanity, saw the potential for our divinization, and when it wasn’t fully realized, God found a creative way to bring it into being. While creation itself, including humanity, came from nothing, the solution to the dilemma came from something– from the stuff humans were made of, from their unique grace-filled imprint of the divine image, coupled with the divine nature itself, in an ultimate act of divine love.

This is a much better story than if Adam and Eve had never eaten the fruit in the first place.


  1. That’s what must be behind the Exsultet’s words:

    O sin of Adam, necessary sin,
    which by the death of Christ is wiped away!
    O happy fault, which found so mighty a redeemer!

    I have always loved those words.


    1. I have too, and have always struggled to phrase the concept in any way that is eloquent. Now, I have the words. Thank you, and pray for us, St. Irenaeus!

  2. There is a theological tradition (Franciscan mainly) that had Adam and Eve not eaten the apple, the Incarnation and all it entails would have happened anyway.

  3. Thank you for this beautiful commentary on the event–I look forward to bringing this framework to my classrooms.

  4. The notion that God the Son would have become incarnate anyway, even if there had been no sin, provides the key that unlocks the very purpose of the creation. The whole of creation, including each one of us, was made for Him, Jesus from the very beginning. In the end, all of it will be recapitulated in Him. The Franciscan tradition in line with this key point of Irenaeus, as mentioned by a contributor above, is articulated above all by Duns Scotus. Once you get hold of this concept, and fully believe it, the elements in revelation are not changed. Of course not – how could they be? But something new happens. These elements are brought into a new relationship with each other, and become restructured in a way that helps us to appreciate them as never before. This can give us wonderful new theological insights into who God is, what He has done for us, and also who we are. Grace is not just salvation from sin, although of course it includes that; it is also, even above all, the elevation of our human nature into a new life of union with God. The story of Salvation now takes place within the story of Creation, of which it is part. God made the Creation so that the Son could freely become part of it, as a human creature. The response to the Fall is no longer the Incarnation, as such. The Incarnation was always intended, and would have happened anyway, even if there had never been any sin. (I’ll continue this in a follow-up post here.)

  5. In that case, the Son’s taking flesh from the Virgin Mary and His being crowned King of the whole Creation would have proceeded as a glorious triumph, without any need of the Cross. However, because man had sinned and thrown the Creation into disorder, Christ had to put this right. His response to sin was the sacrifice of Himself on the Cross, showing us once again how to love unconditionally, and to the end. The Incarnation still culminates in Glory, but it now does so by passing through the Way of the Cross. On that cross He shows us the depths of His love, and makes us capable of loving in the exact same way as He does. This is the ‘Capax Dei’ idea of Irenaeus. We would certainly have experienced a new and elevated Life of Grace through the Incarnation if there had been no sin. But now, because there was sin and Jesus, and because the Incarnate God Himself responded to that sin with the outpouring of love that He showed both for us and for the Father on the cross, an even greater miracle happens. This new Life of Grace that is given to us reaches a completely new level. It now is even greater and deeper, more loving and more glorious, than it would have been, than it would have been if there had never been a Fall into sin. We become capable of a much deeper life of grace – Life with God in Jesus, who is the Life – than ever before. The Cross, followed by the Resurrection and Ascension into Heaven, thus becomes is the salvific event which both restores us and elevates us to a new relationship with God. It is from the Cross that there is now this continual outpouring of His grace, which brings us into a new (grace-filled and, so to speak, grace-oiled) relationship with Him. (A last wee bit still to follow.)

  6. Without that oil, the engine stalls – with it, everything runs smoothly. Everything goes together. Our human nature is elevated by grace, but in no way destroyed by it. This is the new reality, the beginning of the new creation, into which we are baptised. Our actual human condition is transformed and elevated, so that we find – as pure gift – the Divine Life within us. ‘I live, no longer I, but Christ lives in me’, says St. Paul. And yet we are still ourselves – more so than ever. As Irenaeus says: ‘God’s glory is man fully alive.’ We are fully alive when Christ is living within us, leading us on, as we pass through each successive moment of our pilgrimage on our way to our final destiny. Leading us on, that is, to the glory of being completely at one with Him in, and for, all eternity. This is a movement from the Old Creation, which God saw was very (= entirely) good, to the New Creation, which is miles better. Unimaginably better: millions and billions of miles better! The story of our sin and our salvation – of our Fall, and the Redemption won for us and poured out on us by Christ – that story takes place within the story of Creation. The Incarnation – God the Son taking flesh from the Blessed Virgin Mary and becoming man, truly one of us – lies at the heart of that story. It was always intended by God and, despite our sin and infidelity (which obliged Him to respond by accepting death, and not any old death, but death on the Cross) – despite the horror of all that, He never, not even for a single moment, diverted from His intention. God is love, and He showed the unfathomable depth and immeasurable extent of His love, by dying on the Cross for us, and thus loved us infinitely, to the end. In so doing, by His grace He also made us capable of loving Him, and each other, similarly. He transforms us with new capacities we could nave have dreamed of, so that we become ‘Capax Dei’.

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