"In describing the situation at that time Hegesippus goes on to say that until then the Church had remained a virgin, pure and uncorrupted, since those who were trying to corrupt the wholesome standard of the saving message,if such there were, lurked somewhere under cover of darkness.
"But when the sacred band of the apostles had in various ways reached the end of their life, and the generation of those privileged to listen with their own ears to the divine wisdom had passed on, then godless error began to take shape, through the deceit of false teachers, who now that none of the apostles was left threw off the mask and attempted to counter the preaching of the truth by preaching the knowledge falsely so called." -- Eusebius, History of the Church,3:33, written circa 300 A.D.
Eusebius clearly believed that this evil was snuffed out and that the Christianity of his day had triumphed over that campaign of falsehood and apostasy. But every man must judge for himself. In 300 A.D., the Dark Ages, the Inquisition, all lay in the future -- the Church had barely tasted of the temporal power that it would hold for the next 1,000 years.
What were some of the key tenets of the "knowledge falsely so called," Christian-speak for gnosticism?
An incorporeal, unapproachable, incomprehensible God.
De-emphasis -- even abhorrence -- of marriage and family life.
Denial of any literal resurrection.
Judge for yourself how many of these notions made their way into the post-apostolic Christianity.
I first encountered this quote by Eusebius in Nibley, Mormonism and Early Christianity, p. 132, where Nibley states:
"This outbreak of gnostic pretenders ... never could have occurred had apostolic authority remained in the church to overawe the upstarts, or had the true "gnosis" been available to oppose their false ones."
Ultimately, are Eusebius' words the diagnosis of past disease that he intended them to be, or a page for the coroner's report?