Ben: Irenaeus these days is mostly known as a heretic hunter, and even mentions the Gnostic Gospel of Judas which has recently been the subject of major TV discussions on CNN and elsewhere. Why exactly does Irenaeus have such an allergic reaction to all things Gnostic?
Jackson: The simplest answer is that he thinks they are bad readers of scripture. The secret knowledge the Gnostics claimed to possess from Christ unlocked, they claimed, the true meaning of scripture, a complicated theological system which, at its heart, revealed a God who was completely removed from the affairs of humanity and a creation that was inherently evil and therefore unredeemable. For Irenaeus, these theological points fundamentally corrupted the nature of the good news brought by Christ, handed down by the apostles, and revealed in the scriptures when read rightly.
Irenaeus may have left the Gnostics alone; he does not feel the need to comment on every religion or theological group at odds with the emerging claims of the Catholic Church at the end of the second century. But, according to him, these Gnostic groups were quite aggressive and persuasive in their teachings and were leading many Christians away from the Catholic Church and a salvific understanding of the scriptures and the life of faith. As a bishop, he sets out then to confront what he sees as a threat to the spiritual lives of his flock and the integrity of the Christian message by both exposing Gnostic teaching and refuting them by presenting the right way of reading the scripture, the way that was handed down by the apostles.