The authors explain that the gene-driven wiring of the brain to encourage religious beliefs exists because it has been evolutionarily good for us. Stimulating the OAA or the autonomic nervous system can produce calm and a sense of well-being which may be not only pleasant but physically beneficial. Beliefs driven by neurology could reinforce themselves by building myths, encouraging ritual, uniting societies and providing social support from fellow believers. They can check worry about eventual annihilation. They can provide a feeling of control.

Those of a religious bent will find matter to argue with inside these pages, even though the authors are very careful not to argue for or against the existence of deities, only that "the neurological aspects of spiritual experience support the sense of the realness of God." Some may also find disconcerting the idea that ecstasy of religious mysticism may have its roots in the structures that bring on orgasm. Others will find the practical answer to the title's question just too pragmatic and pat, but given the extraordinary research as it now stands, it is the best that science can do as it begins to look into religious feeling: "What we know beyond question is that the mind is essentially a machine designed to solve the riddles of existence, and as long as our brains are wired as they are, God will not go away." This book is a wonderful introduction into this fascinating research.