One man finds in religion his literature and his science, another finds in it his joy and his duty.

A religion which has lost its basic conviction about the interconnection of men with men in their common struggles for the human, will never command belief in the realm of the superhuman.

Religion is the sign of the oppressed creature, the sentiment of a heartless world, and the soul of soulless conditions. It is the opium of the people.

In religion above all things the only thing of use is an objective truth. The only God that is of use is a being who is personal, supreme and good, and whose existence is as certain as that two and two make four.

We must respect the other fellows religion, but only in the sense and to the extent that we respect his theory that his wife is beautiful and his children smart.

Religion has the same relation to man's heavenly condition that mathematics has to his earthly one: both the one and the other are merely the rules of the game. Belief in God and belief in numbers: local truth and truth of location.

Knowledge and history are the enemies of religion.

Religion indeed enlightens, terrifies, subdues; it gives faith, it inflicts remorse, it inspires resolutions, it draws tears, it inflames devotion, but only for the occasion.

True religion is slow in growth, and, when once planted, is difficult of dislodgement; but its intellectual counterfeit has no root in itself: it springs up suddenly, it suddenly withers.

Wherever on earth the religious neurosis has appeared we find it tied to three dangerous dietary demands: solitude, fasting, and sexual abstinence.