You may be interested in Heretics and Heresies by Robert G. Ingersoll, newly released over at Project Gutenberg. This appears to be part of a larger work, The Gods and Other Lectures, of which a number of parts are also available via the Robert G. Ingersoll author page.
“LIBERTY, A WORD WITHOUT WHICH ALL OTHER WORDS ARE VAIN.
WHOEVER has an opinion of his own, and honestly expresses it, will be guilty of heresy. Heresy is what the minority believe; it is the name given by the powerful to the doctrine of the weak. This word was born of the hatred, arrogance and cruelty of those who love their enemies, and who, when smitten on one cheek, turn the other. This word was born of intellectual slavery in the feudal ages of thought. It was an epithet used in the place of argument. From the commencement of the Christian era, every art has been exhausted and every conceivable punishment inflicted to force all people to hold the same religious opinions. This effort was born of the idea that a certain belief was necessary to the salvation of the soul. Christ taught, and the Church still teaches, that unbelief is the blackest of crimes. God is supposed to hate with an infinite and implacable hatred, every heretic upon the earth, and the heretics who have died are supposed at this moment to be suffering the agonies of the damned. The Church persecutes the living and her God burns the dead.”