Modern Halloween celebrations evolved from the Celtic holiday of Samhain. The day was used to celebrate the end of harvesting season and the beginning of winter. The Celts believed that the celebration not only bridged the transition from one season to the next but also connected the living world to the world of the dead. On Samhain, people would light bonfires and wear costumes in order to scare off ghosts who could be roaming during this time of transition.
Pope Gregory III made November 1 All Saints’ Day, which is a time to honor saints and martyrs. The day began to incorporate some traditions of Samhain. The night before All Saints’ Day became known as All Hallows’ Eve and letter evolved into what we now call Halloween. As time passed, the holiday became less about a day of ghosts and more about celebration with costumes and candy. Halloween is now considered a secular holiday
Trick or treating most likely evolved from the All Souls’ Day Parades in England. During this time, poor citizens would go around asking for food. Families would give the beggars pastries called “soul cakes,” and in exchange, they would promise to pray for the family’s dead relatives. Giving out soul cakes was highly encouraged by the church to replace the Sanhaim practice of leaving food and wine for roaming spirits. Later, this practice was replaced by children “going a-souling,” during which they would be given food and money.