The Manichee Heresy
A body of heretics called the Manichees, taught that there are two Gods, one the author of good and the other the author of evil.
A priest in catechism class asked: “Who made the angels?” “God,” answered the children. “And who made the devils?” he continued. No one liked to say that God made the devils, so they all looked at each other and were silent. At length a little girl ventured to say: “Father, God made the angels and some of the angels made themselves devils.”