Saint Irenaeus was born in Asia Minor in the first half of the second century. As a very young man, he came in contact with Saint Polycarp (d. 155) at Smyrna. He met Pope Eleutherius in Rome (177 or 178), and he succeeded the martyr Saint Pothinus as Bishop of Lyons, where he proved to be an attentive, passionate and open-minded shepherd.
Saint Irenaeus, an heir of Saint John the Apostle through the doctrinal formation received from Polycarp, left this precise message for the Church of all times: true Christian theology is born of a practice of listening and reflecting on the Word of God, in accordance with the Church’s teaching of the Faith.
Saint Irenaeus is of capital importance in the theology and mariology of the second century and for the universal Church, which is evidenced by the fact that his formulations were used in the texts of Vatican II.