St. Irenaeus - Defender of the Faith

June 28 is the feast of St. Irenaeus. Irenaeus is known as one of the greatest apologists and teachers in the history of the Catholic Church. He fought and spoke against many of the dangerous heresies of the second century.

Like many of the earliest saints, we know very little about the details of Saint Irenaeus' life. We're going to focus more on his life work in this blog. Read to learn how he fought to preserve truth in the church and its teachings in the second century. But first, this is what we know of Irenaeus.

Irenaeus was born around the year 125 A.D. He was born in one of the provinces of Asia Minor (the Western side of modern-day Turkey). In this area in the early second century, the Christian faith was popular. The work of the first Apostles was still very apparent and alive. When he was young, he likely heard the preaching of now St. Polycarp, who had personally known the Apostles. Inspired by the faith and wisdom of this great preacher, Irenaeus became a priest. Along with a few other missionaries and priests, he moved to serve in Lyons in the region of Gaul. Here, Paganism was still dominant and unfriendly to Christianity.

After the current bishop of Lyons, St. Pothinus, was martyred, Irenaeus was appointed as the second bishop. By the time he was appointed bishop, the blatant persecution of Christians in Lyons had ended, but Gnosticism had begun to run rampant among the diocese. Irenaeus saw how this heresy had begun to pull apart his local Church. He took it as his mission to refute the errors of the heresy and defend the Christian teachings.

Gnosticism, named after the Greek word for 'knowledge,' was a major heresy in the early church. Gnosticism is the belief that humans contain a piece of God and that all physical matter - including bodies and the entire material world - is inherently evil. Gnostics believed that any action done by the body, even horrible sins, were meaningless because it did not pertain to the spiritual.

What made it even worse was that Gnostics claimed that they had secret knowledge directly from Jesus that had been imparted upon just a few disciples. This claim to a "higher knowledge" was very dangerous to the Church in the early years of Christianity.

Irenaeus' first step against Gnosticism was to fully understand and study its beliefs. He soon had learned all of the "secret knowledge" of the Gnostics and was ready to expose its errors to the Church.

He produced a series of five books to clarify the theology of the Christian faith, especially as it related to the heretical teachings involved with Gnosticism. Irenaeus' gifted writing abilities had always been clear and these books are no exception. In these works, he used the teachings of the apostles along with Scripture to cement his points. The books quickly spread and were translated into many languages.

Soon enough, through the popularity of these books, the Gnosticism movement lost its influence and disappeared almost entirely.

Although we don't know much about the end of his life either, it is likely that he died shortly after the year 200 A.D. In 2022, Pope Francis named St. Irenaeus a Doctor of the Church - specifically with the title "Doctor of Unity." Irenaeus played a pivotal role in keeping the early Church together, likely impacting the spread and growth of the Church for the next century to come.