Augustine of Hippo, on 1John 4:1

“Dearly beloved, believe not every spirit, but try the spirits if they be of God: because many false prophets are gone out into the world.”

“"Beloved, believe not every spirit." Because he had said, "In this we know that He abideth in us, by the Spirit which He hath given us." But how this same Spirit is known, mark this: "Beloved, believe not every spirit, but prove the spirits whether they be from God." And who is he that proves the spirits? A hard matter has he put to us, my brethren! It is well for us that he should tell us himself how we are to discern them. He is about to tell us: fear not.”

Imported from an open dataset — not yet checked against the printed edition.