This book isn’t concerned with the truth of claims made by religions, but is merely interested in examining belief from cultural, behavioral, psychological, philosophical, and scientific perspectives.

The big question here is: why does religion exist? What purpose does it serve? What aspects of religion can be explained by science, and what makes religions similar and different?

The book covers much that Daniel Dennett’s book "Breaking the Spell: Religion as a Natural Phenomenon" does, but Shermer’s writing style is far easier to follow (I was only able to get about 90 pages into BtS before I stopped). Dennett’s book is probably more thorough, but Shermer is more accessible.

This book taught me a great deal about the origins of religious thought, as well as how people think in general, and how our thinking behaves in ways we don’t expect it to.