The most frightening belief systems are those that are apocalyptic...in the original Abrahamic belief system , Judaism , the belief is there will be a Messiah that will deliver the faithful to a purely good new era overseen by god; Christianity , the second to arise from the Abrahamic tradition, believers that there will be an apocalypse , Armageddon, with Jesus ( the second coming) returning to earth and leading the pious , the saved, to heaven(Newton calculated that it would occur in 2060); the third of the Abrahamic tradition, Islam, that there will be a Day of Judgement, the annihilation of all life, followed by resurrection and judgement by Allah/ God.

There are other belief systems with their end of the world predictions.

The problem rises that there are fanatical believers , who, thanks to the era of nuclear weapons , who are now in a position to precipitate the predicted apocalypses....