Halloween's origins can be traced back to the ancient Celtic festival known as Samhain, which was held on November 1 in contemporary calendars. It was believed that on that day, the souls of the dead returned to their homes, so people dressed in costumes and lit bonfires to ward off spirits.

In the 8th century, Pope Gregory III, in an attempt to get away from pagan rituals, instituted All Hallows Day on November 1 to honor all those who had died. The day before All Hallows Day became All Hallows Eve, later shortened to Halloween.

The Bible doesn't mention Halloween because it didn't exist in biblical times. Indeed the name is likely a contraction of All Hallows' Eve, the day before the feast of All Hallow or All Saints. There is a possibility though that the celebration was influenced by pagan ritual like Samhain.

Halloween, a holiday observed on October 31 and noted for its pagan and religious roots and secular traditions. In much of Europe and most of North America, observance of Halloween is largely nonreligious, celebrated with parties, spooky costumes, jack-o'-lanterns, pumpkin carvings, and the giving of candy.