You might have heard about the bunches of heresies that popped up in the early centuries of Christianity. But historians don't generally like using the term "heresy" to describe these groups. Is there ...

St. Irenaeus, "Against All Heresies," c. 180 A.D. "In this order, and by this succession, the ecclesiastical Tradition from the Apostles, and the preaching of the Truth, have come down to us.