With a sweeping and witty examination of religion's history, alongside fascinating doses of science and philosophy, Craig A. James has opened an exciting new way to understand the pervasiveness of modern religions. Thousands of authors have written about the how, when, and what of religion, but few have dared ask "Why?" The Religion Virus will finally give you that "Aha!" moment—that is, why religion evolved from simple spirituality into the vast monotheistic system that pervades Western society.

At any given moment, tens of thousands of religions, branches, sects, and belief systems are competing in a "survival of the fittest" battle as ferocious as anything in nature. These belief systems are locked in an endless fight for dominance, and with each generation there are winners and losers: only the “fittest” survive. Just like biological life, ninety-nine percent of the world’s religions are extinct, but the ones that survived into the modern era are quite remarkable. These religions are the very strongest and best—the fittest.

The trouble is, “fitness” for a religion has little to do with truth. Instead, religions have "learned" to prey on our biggest hopes, our worst fears, our biological instincts, and our heartfelt desires. It has taken thousands of years of evolution, but those years have honed religion to near perfection.

Whatever your beliefs, when you finish the book’s last chapter, your understanding of religion will forever be changed.