While Halloween has been seen as a largely secular holiday for many years in the United States, it has deep roots in the Christian tradition—and many pre-Christian European cultures. Because of this mixed legacy, families in many faith traditions—Christian, Jewish and Muslim among them—routinely face questions about whether or not the holiday aligns with the principles of their faith.
Halloween originated as a Celtic holiday called Samhain celebrated 2,000 years ago. It marked the end of the Celtic year and the beginning of a dark, cold winter. It was said at the time that night ghosts of the dead roamed the earth. During the Celtic festival of Samhain, people would light bonfires and wear costumes to ward off ghosts. Celts believed that on the night before the new year, the boundary between the worlds of the living and the dead became blurred.
In the eighth century, Pope Gregory III moved All Saints Day, a holiday to honor all the saints who did not already have their own day, from May 13 to Nov. 1. The reason for this move is debated, but at the time Samhain was gaining in popularity, and this was the pope’s way of Christianizing a pagan holiday.
By the 9th century, the influence of Christianity had spread into Celtic lands, where it gradually blended with and supplanted older Celtic rites. In A.D. 1000, the church made November 2 All Souls’ Day, a day to honor the dead. All Hallows Eve, named for the day before All Saints Day, was the new “Christian” version of Samhain.
Halloween came to America in the early 19th century but gained popularity when the Irish immigrated to America during the Irish Potato Famine. They brought along their Halloween traditions of dressing up and trick-or-treating.
All Souls’ Day was celebrated similarly to Samhain, with big bonfires, parades and dressing up in costumes as saints, angels and devils. The All Saints’ Day celebration was also called All-hallows or All-hallowmas and the night before it began to be called All-Hallows Eve and, eventually, Halloween.
Between 1920 and 1950, the centuries-old practice of trick-or-treating was also revived. Trick-or-treating was a relatively inexpensive way for an entire community to share the Halloween celebration. In theory, families could also prevent tricks being played on them by providing the neighborhood children with small treats.