It is an old story that the Devil’s best trick has always been to encourage people not to believe in him and judging from general opinion about him today he has had a good deal of success: a figure of fun or a possibility than men from Mars or the latest Thing from Outer Space in science fiction. Yet Christians believe in the existence of angels as part of God’s creation and in the fallen angels of whom Satan is the chief and they pray daily to be delivered from him and from “all wicked spirits who wander through the world for the ruin of souls”. How do they justify such a belief in the world of today? To believe in the existence of evil and the catastrophic consequences of human pride is easier nowadays than it was fifty years ago, but many people still baulk at the idea of the Devil’s having anything to do with them. This book examines the scriptural basis of belief in the Devil, cases of possession in the Gospels, in the early centuries after Christ and in modern times, the phenomenon of Satanism and its various disguises, and Satan’s relations with mankind today.