In his war on Nicolaitism, Gregory was sustained by ancient laws of the Roman Church, but not by the genuine spirit of Christianity. Enforced clerical celibacy has no foundation in the Bible, and is apt to defeat the sacerdotal ideal which it was intended to promote. The real power and usefulness of the clergy depend upon its moral purity, which is protected and promoted by lawful matrimony, the oldest institution of God, dating from the paradise of innocence.