"In 1553, a Spanish scientist, lawyer, physician and amateur theologian named Michael Servetus arrived in Geneva. Servetus was the first person to postulate on circulation of the blood. Servetus had earlier published On the Errors of the Trinity (1531) in which he questioned the divinity of Christ. He also sent Calvin a copy of the Institutes with “corrections” noted in the margin. Servetus tried to convince the people that he was correct, and was arrested for his trouble. During his trial, Calvin was so incensed that that he blurted out, “May little chickens dig out his eyes a hundred thousand times.” Servetus was tried as a heretic and burned at the stake." Z,C&A
.... even as there shall be false teachers among you, who privily shall bring in damnable heresies, even denying the Lord that bought them, and bring upon themselves swift destruction.
2 Peter 2:1