Religion in Ancient History (1969) includes 25 essays on comparative religion, covering the origin of religion, and studies of the religions of the peoples of ancient Egypt, Mesopotamia, Israel, Greece and Iran. It also includes essays on key ideas such as creation, death, time, the soul, and the judgement of the dead, and studies of figures like Osiris, Akhenaten, Job and Zarathustra. The book also deals extensively with religious ideas, men and events in the first three centuries A.D. and the spread of early Christianity.