7.4 million self-identified atheists; 1.1 billion are religiously "unaffiliated"
There is no God or divine beings.
Influential works include those by Marx, Freud, Feuerbach, Voltaire, and Mark Twain. Notable modern authors include Richard Dawkins and Carl Sagan.
Atheism is the lack of belief in any gods. It is not a religion, but a worldview that looks to science and reason instead of religion to answer the "big questions."