Many commentators today claim that religion is dangerous and harmful. In addressing this question, Keith Ward begins by defining what religion actually is and how most human harm has been caused. He then looks at why people say that religion is dangerous, focusing particularly on religious wars and conflicts and on specific attacks on religion, such as the claim that God is wrathful, that religion is intolerant, that religious morality is primitive and cruel.

Keith Ward argues that religion produces great good - for example, in terms of hospitals, the abolition of slavery, great art and music, moral heroism, and philosophy and science. Religion, he concludes, is the best rational basis for morality.