When Paul encountered the magician and false prophet Bar-Jesus, he was uncompromising in his retort:
Act 13:10 and said, “You who are full of all deceit and fraud, you son of the devil, you enemy of all righteousness, will you not cease to make crooked the straight ways of the Lord?
Act 13:11 “Now, behold, the hand of the Lord is upon you, and you will be blind and not see the sun for a time.” And immediately a mist and a darkness fell upon him, and he went about seeking those who would lead him by the hand.