Among early church fathers, Irenaeus of Lyons was one of the foremost champions of “orthodoxy” during the second century. His work and writings helped defend the life and person of Jesus against the divisive and dismissive doctrines of the Gnostics.
The exact year of Irenaeus’s birth is unknown, most modern scholars agree on 130 CE. He grew up in Smyrna and learned about Jesus from the martyr Polycarp, a student of the apostle John. Irenaeus called Polycarp a “powerful and formative presence during the early years of his life,” and he had fond memories sitting at the feet of the martyr and writing the lessons on his heart.
As a young man, Irenaeus moved to Lyons and became a missionary in Gaul, working among the Celts, though most of his work was toward the Greeks and Romans in the region. Gaul had been conquered by Julius Caesar in 52 BC, and many Romans moved into Gaul to maintain a Roman presence.
The churches in Lyons and nearby Vienne suffered great persecution this time. The church historian, Eusebius, preserved a letter from these churches to the churches in Asia Minor recounting the brave Christians in Gaul who endured fierce torture and were thrown to the wild beast. The letter, delivered by Irenaeus, memorialized their struggles and deaths.
Irenaeus became bishop of Lyons around 177 CE and held that position until his death in 200-203. He once wrote a letter to Victor, the bishop of Rome, encouraging him to not divide the church over the observance of Easter. Eusebius, again preserving part of this letter, says Irenaeus lived up to his name, which means “peaceful.”
During the second century there was a proliferation of new ideas about Jesus and the church. Without a standardized canon of scriptures, many of these ideas threatened to become mainstream. Irenaeus stood at the forefront of the defense of orthodoxy. He was one of the first to push for an authorized list of scriptures to defend the church against false teaching. He was the first to use the phrase “New Testament” to distinguish the old Jewish writings from the new Christian writing. His magnum opus was a five-volume work, Against Heresies, that focused on the heresies of Gnosticism in the late second century.
Irenaeus sought to establish three things: (1) churches should draw their authority from teaching the same doctrines the apostles taught; (2) churches needed to use scriptures from both testaments, written by apostles and prophets; and (3) the church needed to interpret the scriptures in light of apostolic teaching. These became the basis on which Irenaeus opposed Gnosticism.
The threads of Gnosticism began during the first century and were addressed by Paul and John. However, these doctrines proliferated in the second century after the apostles had passed and the writings were being established. Irenaeus opposed Gnosticism which produced a spiritual elitism because its followers felt their knowledge was superior to ordinary Christians. Gnosticism also denied the efficacy of Jesus’s actions in history by saying knowledge brought salvation instead of the blood of Christ, which Irenaeus recognized as a challenge to the clear teaching of the apostles. Finally, Irenaeus saw their “bible code” interpretation as an affront to the meaning scripture. He described it as taking a mosaic of a king, rearranging the pieces to form the image of a fox and saying that the fox was intended all along.
His writing helped minimize the efforts of the Gnostics. They also helped establish the identity of Jesus as the Christ, the Son of God, and defended the teachings of the scriptures. Irenaeus didn’t get everything right, but his work is foundational for defending the bible’s teaching on the divine identity of Jesus.
Today, there are still some who turn to the fanciful ideas of Gnosticism, or who look for secret codes in the Bible. However, their efforts and ideas are inconsequential in the world and in the church. This is partly due to the Irenaeus’s efforts to thwarted those trying to redefine Christ and the church in the second century.