Some years ago, while I was a student priest in Rome, a classmate and I decided to take a few days away from the Eternal City. We chose to go to France and visit some of the holy places throughout that country.

While we weren’t expecting to go through Lyons, our route inadvertently took us through the antique city. For two students of theology, the city immediately screamed out the name “Irenaeus” and brought to mind the saint’s rich contribution to the Christian intellectual and spiritual tradition.

In our zeal, we scoured the city looking for where the body of the saint rested so we could offer some prayers and ask for his intercession. In the different churches of Lyons, we were surprised that one person after another – not only did not know where Irenaeus was resting – but didn’t even know who he was. This was Lyons.

It’s understandable, even if regrettable, that many Christians do not know this early father of our faith, but for people in Lyons – the saint’s own city – not to know who he was is just unsettling. It would be as surprising if someone working in a church in Krakow didn’t know who John Paul II was.

The experience raises some questions. Should we know who Saint Irenaeus is? Does he have something to contribute to our understanding and living out of our discipleship in our world today?

To both of these queries, Pope Francis answers with a loud and robust “yes.” This past week, the pope took the unexpected action of naming the early father a Doctor of the Church. By giving the Church only her 37^th Doctor, Pope Francis is asserting – with the highest title that can be bestowed upon a person – that Irenaeus should be known by believers today and that he has something essential to teach us.

Who, then, was Irenaeus? What are his lessons for us today?

The saint was born in Smyrna (in modern day Turkey) around 125 AD. He was raised in the city in a Christian home, which was rare at that time. He grew in his belief and love for Jesus Christ through the preaching of Saint Polycarp, a disciple of the Apostle John. Ireneaus’ faith, therefore, was within the early apostolic tradition and very near to the public ministry of the Lord Jesus.

The saint’s love for the Lord led him to ordination and he was eventually sent to Lyons as its second bishop, succeeding the martyred Pothinus. The need for a bishop in France at this early time in the Church’s life indicates her tremendous growth and expansion. And so, while the saint was a great teacher of the faith, he was also a shepherd in the midst of the struggles and difficulties of the Church in the trenches.

In terms of his teaching, Irenaeus vigorously defended the Incarnation of Jesus Christ and his identity as true God and true man. Such a belief was held by believers throughout the Church, in both the culturally diverse East and West. While later there would be schisms and divisions, here Irenaeus shows himself a teacher of both “lungs” of the universal Church.

The saint was adamant in his instruction that the Gospel was for every man and woman. There were no elites and no esoteric groups of people within the human family. The Gospel was given through the incarnation of the Son of God. It came to us from the human experience and was, therefore, open and offered to all. In this way, Irenaeus became a voice of the impartiality of God and the all-embracing nature of the Gospel of Jesus Christ.

Among some of Irenaeus’ most notable contributions, which can still help us to today, were his immense love for the Sacred Scriptures, the apostolic tradition, and the teachings of the Church’s shepherds. The saint named the “Old” and “New” Testaments, as well as gave us one of the earliest list of the books of the New Testament. He provides us with one of the first lists of the succession of the Bishops of Rome, which he saw as the glue of the apostolic tradition. And he revered the fellow bishops of his day, who were stalwart and fierce in their preaching, with many of them – like Irenaeus himself – dying martyrs.

In all of these ways, Irenaeus is a help to us today. He has rightly been given the designation of “Doctor of Unity,” as his example and intercession can help us to see what we share in common, what sources of unity we’ve been given, and how we are called to live as disciples of the God-Man, Jesus Christ.

(Incidentally, for anyone who’s interested, the majority of Irenaeus’ body was subject to sacrilege and thrown in the river of Lyons during the French Revolution.)

Follow Father Jeffrey Kirby on Twitter: @fatherkirby