If a man really believes that God once upheld slavery; that he commanded soldiers to kill women and babes; that he believed in polygamy; that he persecuted for opinion's sake; that he will punish forever, and that he hates an unbeliever, the effect in my judgment will be bad. It always has been bad. This belief built the dungeons of the Inquisition. This belief made the Puritan murder the Quaker.

The Works of Robert G. Ingersoll: Interviews (ed. 1900)