Saint Irenaeus (+202 A.D.), bishop of Lugdunum – now Lyons – in the second century of the Church’s existence, a disciple of the martyr Saint Polycarp, who was in turn a disciple of Saint John the Apostle, is himself not only one of the clearest links to apostolic Tradition, but his writings and thoughts form the basis of what we now know as that queen of the sciences, ‘theology’, the application of reason to the revealed word of God.
Raised in Asia Minor in a Christian household, near what is now Izmir, Turkey, Irenaeus, whose name means ‘maker of peace’, traveled west, was ordained a priest, and, when his spiritual and intellectual gifts were clearly recognized, was eventually consecrated bishop in the Roman territory of what is now France.
Irenaeus wrote much, and much of what he wrote thankfully survives. His main battle was against the Gnostics, a powerful sect that claimed to have secret, esoteric knowledge of the path to ‘salvation’, often bizarre and dualistic (that matter and the body are evil). They claimed this knowledge was from Christ Himself, not the Magisterium, thereby separating themselves from the hierarchical and Catholic Church. They were the first real ‘heretics’, literally, those who create a schism or rip in the Body of Christ, and since that day there have always been those, especially those gifted with some degree of intelligence, but with a zeal and a critical spirit that outstrip their natural gifts and what Faith they have, who think they know better than the Church, the Pope, the bishops, the Magisterium. We need not look far for current examples.