Is Halloween a purely secular holiday or does it have its origins in religion?
Originally it was a Celtic pagan holiday. I believe it was their new year, when the harvest ended, and a day when the dead were allowed to come back to earth, so people disguised themselves to avoid them. Later it was turned into All Hallowed Evening (or Halloween), the night before All Saints’ Day, when Christianity took over and subverted all the pagan holidays they couldn’t get rid of to become Christian holidays. Today, there is no real religious input into it except for the Hell Houses at a few fundamentalist churches. It is now just an excuse to eat too much candy, watch some trashy gore flicks, and see girls dress slutty.
