In case you haven’t heard, the world is supposed to end at midnight on December 21—this year.At least, that’s according to some popularized interpretations of what the Mayans said. But predictions of the end times are hardly a new or unusual thing. For Christians, prophecies of an imminent apocalypse are just about as old as the Church itself. Those predicting the end were an eclectic lot, with wild ideas and strange teachings. They include an antipope, a saint who rode the devil like a donkey, and cultish charismatics who dressed like harlots. Some were inspired by their false interpretations...