An essential feature of religious experience across many cultures is the intuitive feeling of God's presence. More than any rituals or doctrines, it is this experience that anchors religious faith, yet it has been largely ignored in the scientific literature on religion. Biologist John Wathey takes the reader on a scientific journey to find the sources of religious feeling and the illusion of God's presence. His book delves into the biological origins of this compelling feeling, attributing it to innate neural circuitry that evolved to promote the mother-child bond. Dr. Wathey, a veteran neuroscientist, argues that evolution has programmed the infant brain to expect the presence of a loving being who responds to the child's needs. As the infant grows into adulthood, this innate feeling is eventually transferred to the realm of religion, where it is reactivated through the symbols, imagery, and rituals of worship. The author interprets our various conceptions of God in biological terms as illusory supernormal stimuli that fill an emotional and cognitive vacuum left over from infancy.