Stephen Asma argues that, like art, religion has direct access to our emotional lives in ways that science does not. Yes, science can give us emotional feelings of wonder and the sublime—we can feel the sacred depths of nature—but there are many forms of human suffering and vulnerability that are beyond the reach of help from science. Different emotional stresses require different kinds of rescue. Unlike secular authors who praise religion's ethical and civilizing function, Asma argues that its core value lies in its emotionally therapeutic power.

No theorist of religion has failed to notice the importance of emotions in spiritual and ritual life, but truly systematic research has only recently delivered concrete data on the neurology, psychology, and anthropology of the emotional systems. This very recent "affective turn" has begun to map out a powerful territory of embodied cognition. Why We Need Religion incorporates new data from these affective sciences into the philosophy of religion. It goes on to describe the way in which religion manages those systems—rage, play, lust, care, grief, and so on. Finally, it argues that religion is still the best cultural apparatus for doing this adaptive work.