Why celebrate Halloween?

The word "Halloween" comes from All Hallows' Eve and means "hallowed evening."
The history of Halloween dates back to a pagan festival called Samhain.
Hundreds of years ago, people dressed up as saints and went door-to-door, which is the origin of Halloween costumes and trick-or-treating. Halloween, contraction of All Hallows' Eve, a holiday observed on October 31, the evening before All Saints' (or All Hallows') Day. The celebration marks the day before the Western Christian feast of All Saints and initiates the season of Allhallowtide, which lasts three days and concludes with All Souls' Day.