For there must be also heresies among you.... This is a reason why he was ready to believe there might be something of truth in the report he had received of the divisions among them; for if there were heresies, false doctrines, and bad principles, among them, such as were subversive of the fundamentals of Christianity, as the denial of the resurrection of the dead, &c.
it was no wonder that there were schisms and factions among them, since heresies generally issue in them.