" In sermon after hectoring sermon delivered by this new generation of rigidly unbending preachers, the people’s choice was made clear. In deciding who to worship, congregations were not choosing between one god and another. They were choosing between good and evil; between God and Satan. To allow someone to follow a path other than the true Christian one was not liberty; it was cruelty. Freedom to err was, Augustine would later vigorously argue, freedom to sin – and to sin was to risk the death of the soul. ‘The possibility of sinning,’ as one pope later put it, ‘is not freedom, but slavery’. To allow another person to remain outside the Christian faith was not to show praiseworthy tolerance. It was to damn them. "

― Catherine Nixey , The Darkening Age: The Christian Destruction of the Classical World