The Essence of Christianity

In The Essence of Christianity-this is the classic 1853 translation of the 1841 German original-Feuerbach discusses the "true or anthropological" root of religion, exploring how everything from the nature of God to the mysteries of mysticism and prayer can be viewed through such a prism. He goes on to examine the "false" essences of religion, including contradictions in ideas of the existence of a deity, and then how God and religion are merely expressions of human emotion.
This is essential background reading for understanding everything from Marx's Communist Manifesto to modern apolitical philosophies of atheism.