Halloween is a very Christian Holiday. It's the day before All Souls Day, and was orginally called 'All Hallow's Eve.' I's also the day Martin Luter nailed his 95 Thesis on the door of the church in Wittenburg, Germany.
Hey, if your not allowed, or your parents don't let you, that's fine and all, but accuatly, it's a more religious holiday then most people think.