The Book of Revelation is the strangest book in the Bible, and the most controversial. Instead of stories and moral teaching, it offers only visions—dreams and nightmares, the Four Horsemen of the Apocalypse, earthquakes, plagues and war. In the climactic battle scene, Jesus appears as a divine warrior, Satan is thrown into a pit, and all humans who had died faithful to God reign over the earth for 1,000 years.

The author, John of Patmos, was a Jewish prophet and a follower...