Doomsday predictions, whether secular or religious, often attract those who feel the world is unsalvageable. Sometimes the world-ending catastrophe is nuclear winter; sometimes it’s the Mayan apocalypse. But religious doomsday groups often draw on mainstream faith, said Stephen Kent, a sociologist at the University of Alberta.
"Almost all apocalyptic beliefs show Christian influence," Kent told LiveScience.
That's because a central tenant of the faith is that Jesus will return — although many mainstream Christians point to the Bible verse Matthew 24:36 to condemn doomsday prophets such as Camping. That verse says that no one knows the day or hour of the end, "not even the angels in heaven."
Those who try to predict when doomsday will occur often focus on the world's sin. Camping, for example, has said that God left all churches in 1988, leaving Satan to rule those institutions. Famous 1800s doomsday prophet William Miller, who predicted that the end would come on Oct. 22, 1844, was "disillusioned with humanity," Kent said. [Read: Oops! 11 Failed Doomsday Predictions]