“One of the greatest tragedies in the history of the Christian Church was the justification of religious persecution and holy wars. In the beginning of the 5th century AD Augustine (354 – 430), one of the greatest theologians, used Jesus’ words to justify persecution of heretics. According to James Carroll. ‘ It was the late Augustine who, no longer depending on the force of reason, justified the use of coercion in defending, and spreading, the orthodox faith: in being first compelled by fear or pain, so that they might afterward be influenced by teaching’.
Augustine who had to face the heresy of Donatism made an unfortunate interpretation of Jesus parable of the banquet (Luke 14:16-24). A master organized a great supper and invited his friends. They declined the invitation. In the context of the story this was very humiliating for the master. The dinner was ready and nobody was there. The master decided to send his servants out to the streets and to come back with all those they can find. His order in verse 23 (KJV) is to ‘Compel them to come in.’ The Greek verb anagkazo can be translated as to constrain or to compel, whether by force or by persuasion… Augustine's view formed the basis of the doctrine and practice of the Middle Ages. It opened the way for the inquisition. A few centuries later the great theologian Thomas Aquinas (AD 1224-1274) went even further. He justified the death penalty for heretics.” (John Gratz, Issues of faith & Freedom, 2008, p.32-33).