Give any orthodox church the power, and to-day they would punish heresy with whip, and chain, and fire. As long as a church deems a certain belief essential to salvation, just so long it will kill and burn if it has the power. Why should the church pity a man whom her God hates? Why should she show mercy to a kind and noble heretic whom her God will burn in eternal fire? Why should a Christian be better than his God?

Robert Green Ingersoll (1833-1899) American lawyer, agnostic, orator

Lecture (1874-05-03), “Heretics and Heresies,” Free Religious Society, Kingsbury Hall, Chicago
    (Source)

Collected in The Gods and Other Lectures (1876).