That old enemy of mankind, the devil, has no more subtle device for ruining souls than that of spreading false doctrine. Outside the church he is ever persuading men to maintain destructive superstitions. Like a pirate, his object is to “sink, burn and destroy.”

Inside the church he is ever laboring to sow heresies, to propagate errors, to foster departures from the faith. If he cannot prevent the waters flowing from the Fountain of Life, he tries hard to poison them. If he cannot destroy the medicine of the Gospel, he strives to adulterate and corrupt it.

~ J.C. Ryle

Warnings to the Churches, “Divers and Strange Doctrines”, [Carlisle, PA: Banner of Truth, 1967], 72.