Every religion, ancient or contemporary, believes in the existence of spiritual creatures and powers whose existence can’t be proven with logic or science. The spirits are either good and serve God’s will (angels in Western culture) or are evil and corrupt, deceive, and hurt humans in the service of their leader’s (Satan) devious plan and purpose.
From ancient Greece, Persia, Israel and Egypt to medieval Europe and Japan there have been many tales told by people who have claimed to have encountered demons. However, despite the fact that none of these stories can be proven, the blind faith and superstitions passed from generation to generation will make most of us keep the lights on at night.
