The writings of St. Irenaeus entitle him to a high place among the fathers of the Church, for they not only laid the foundations of Christian theology but, by exposing and refuting the errors of the gnostics, they delivered the Catholic Faith from the real danger of the doctrines of those heretics. It was Irenaeus who first proposed the four Gospels we revere today be accepted as canonical, and the doctrine of apostolic succession.
He was probably born about the year 125, in one of those maritime provinces of Asia Minor where the memory of the apostles was still cherished and where Christians were numerous. He was most influenced by St. Polycarp who had known the apostles or their immediate disciples
Many Asian priests and missionaries brought the gospel to the pagan Gauls and founded a local church. To this church of Lugdunum (Lyon), Irenaeus came to serve as a priest under its first bishop, St. Pothinus, an oriental like himself.
During the persecution of Marcus Aurelius, the Roman Emperor from 161–180, the clergy of that city, many of whom were suffering imprisonment for the faith, sent him in 177 to Rome with a letter to Pope Eleutherius concerning the heresy of Montanism and that occasion bore emphatic testimony to his merits.
This mission explains how it was that he was not called upon to share in the martyrdom of St Pothinus during the terrible persecution in Lyons. When he returned to Lyons it was to occupy the vacant bishopric. By this time, the persecution was over. It was the spread of gnosticism in Gaul, and the ravages it was making among the Christians of his diocese, that inspired him to undertake the task of exposing its errors. He produced a treatise in five books in which he sets forth fully the inner doctrines of the various sects, and afterwards contrasts them with the teaching of the Apostles and the text of the Holy Scripture. His work, written in Greek but quickly translated to Latin, was widely circulated and succeeded in dealing a death-blow to gnosticism. At any rate, from that time onwards, it ceased to offer a serious menace to the Catholic faith.
The date of death of St. Irenaeus is not known, but it is believed to be in the year 202. The bodily remains of St. Irenaeus were buried in a crypt under the altar of what was then called the church of St. John, but was later known by the name of St. Irenaeus himself. This tomb or shrine was destroyed by the Calvinists (Huegenots) in 1562, and all trace of his relics seems to have perished.
St. Irenaeus, was a pupil of Polycarp, and in a letter to Florinus, he recounts learning from his teacher:
“I remember the events of that time more clearly than those of recent years. . . . I am able to describe the very place in which the blessed Polycarp sat as he discoursed, and his goings out and his comings in, and the manner of his life, and his physical appearance, and his discourses to the people, and the accounts which he gave of his intercourse with John and with the others who had seen the Lord. And as he remembered their words, and what he heard from them concerning the Lord, and concerning his miracles and his teaching, having received them from eyewitnesses of the “Word of life” (1 John 1:1), Polycarp related all things in harmony with the Scriptures.”. (-Eusebius, Church History, V.20)
St. Irenaeus had the great gift of sitting at the feet of a theologian and bishop trained by the Theologian—the one Apostle who was with Mary at the Crucifixion of our Lord! And what a great gift we have in the writings of Irenaeus, Polycarp, Ignatius, Clement, and many other early Fathers of the Church.
We learn another important fact from St. Irenaeus: these Fathers were not just Christian intellectuals, leaders, or martyrs; they were successors of the Twelve.
“It is within the power of all . . . who may wish to see the truth, to contemplate clearly the tradition of the apostles manifested throughout the whole world; and we are in a position to reckon up those who were by the apostles instituted bishops in the Churches, and [to demonstrate] the succession of these men to our own times. (-Against Heresies, III.3.1)
Already in the second century, St. Irenaeus was encountering a great number of people who were distorting the Scriptures and the Gospel message.
It is not thou that shapest God
it is God that shapest thee.
If thou art the work of God
await the hand of the artist
Who does all things in due season.
Offer Him thy heart,
soft and tractable,
and keep the form
in which the artist has fashioned thee.
Let thy clay be moist,
lest thou grow hard
and lose the imprint of his fingers.
“Irenaeus did not stop at defining the concept of Tradition. His tradition, uninterrupted Tradition, is not traditionalism, because this Tradition is always enlivened from within by the Holy Spirit, Who makes it live anew, causes it to be interpreted and understood in the vitality of the Church.” —Pope Benedict XVI
O God, who called the Bishop Saint Irenaeus
to confirm true doctrine and the peace of the Church,
grant, we pray, through his intercession,
that, being renewed in faith and charity,
we may always be intent on fostering unity and concord.
Through our Lord Jesus Christ, your Son,
Who lives and reigns with You in the unity of the Holy Spirit,
one God, for ever and ever. Amen.
-from The Roman Missal