The cruel persecutions instituted by the authorities with a view to securing conformity increased the number and fanaticism of the schismatics and heretics, and created among them a widespread belief that the reign of Antichrist, foretold in the Apocalypse, was at hand.
While severely condemning, both Irenaeus and Tertullian distinguished schismatics from heretics."
Though we are by no means entitled to say that they acknowledged orthodox schismatics they did not yet venture to reckon them simply as heretics.
Cyprian was the first to proclaim the identity of heretics and schismatics by making a man's Christianity depend on his belonging to the great episcopal church confederation.
The distinction between heretics and schismatics was preserved because it prevented a public denial of the old principles, because it was advisable on political grounds to treat certain schismatic communities with indulgence, and because it was always possible in case of need to prove heresy against the schismatics."(Harnack's History of Dogma, ii.