The Revelation to John is the strangest book in the New Testament. Its visions of destruction and transformation stimulate the imagination even as they seem to defy explanation. Over the centuries it has provided a basis for all kinds of speculation about the future, but its real message is a timeless challenge to the church. This commentary shows the importance of reading Revelation alongside Old Testament books such as Daniel, Ezekiel and Zechariah. Like these other prophecies, Revelation shows the history of the world from the viewpoint of heaven. It promises God's intervention to bring about his rule and save his people, but it is also a call to witness in the face of a world seduced by wealth and power, and misled by false religion. While it was originally a message to the churches of John's own time, it also has a great deal to say to Christians today.