The early Church Fathers were not private thinkers offering isolated opinions. They wrote as witnesses within the life of the Church, reasoning from what had been received from the Apostles rather than from personal insight or innovation. In this installment of Fathers Know Best, St. Irenaeus of Lyons explains why the Church’s unity of belief across time and place is not accidental, but a sign of fidelity to the truth.
St. Irenaeus of Lyons
Against Heresies, Book I, Chapter 10
“The Church, though dispersed throughout the whole world, even to the ends of the earth, has received from the apostles and their disciples this faith…
Although scattered throughout the whole world, the Church carefully preserves this faith, as if occupying but one house. She believes these things as if she had but one soul and one and the same heart…
The Churches founded in Germany do not believe or hand down anything different, nor do those in Spain, nor those in Gaul, nor those in the East, nor those in Egypt, nor those in Libya.”
Reflection
Irenaeus treats unity of belief as evidence of truth. Across languages, cultures, and geographic regions, the Church professes the same faith—not because it’s enforced, but because it is received. Truth, for him, is not something locally generated or personally refined. It is something handed on, and then lived and acted upon. It’s more deeply understood progressively but it isn’t progressed from (broken away from)
This is why heresy is more than holding an incorrect opinion. It is a rupture. To teach differently from what the Church has always believed everywhere is to step outside the shared mind of the Church. Innovation in doctrine is not development so much as isolation from the Church (the Body, and the members). It’s separation; putting the person outside of communion (excommunicatio in Latin, excommunicated in English, meaning outside of communion).
Truth is authenticated by continuity. Irenaeus already grasped that, long before the Church later articulated it clearly. The Catechism defines heresy as the obstinate denial or doubt of a truth that must be believed with divine and Catholic faith. Irenaeus shows us the deeper instinct behind that definition. Truth doesn’t originate with the individual. It comes from God (It’s God Himself) and is entrusted to the Church, not invented by her.
The malady of modern man is the errant belief that truth begins with the self. This illness has infected Christianity as well. Catholics and non-Catholics alike often believe that truth begins with what feels right or seems most reasonable to them. Irenaeus begins elsewhere—with what has been received from God through His Church. Different languages, same doctrine. Christian faith is not self-generating. No one can recreate it from scratch. It exists only because something objective is handed on. Because revelation is received, not invented, the faith remains alive only through faithful transmission.
Truth is not invented by the present. It is guarded from the past and handed to the future.