As the Christian Church grew, Samhain blended with a Christian holiday known as All Saints’ Day, All Hallows’ Day, or Hallowmas, which was originally observed in May but later moved to November 1. It was a time for believers to honor and remember those who had passed on to heaven. This blending was not coincidental. Early Christian leaders told their missionaries that if they wanted to convert pagans to Christianity, they shouldn’t waste time on trying to suppress their rituals and practices, but rather they should consecrate those practices to Christ and incorporate them wherever possible. This had the effect of establishing Christianity among the pagans — but it also preserved many of the pagan practices instead of quashing them. So Samhain and All Saints’ Day rituals influenced each other and eventually merged, and that is when we begin to see the traditions that we associate with Halloween today.
One such tradition was the practice of “souling,” common in Britain and Ireland in the Middle Ages. Poor people would go door to door on Hallowmas and offer to pray for the souls of the family’s dead relatives, in exchange for an offering of food. It mingled with the practice of “mumming”: dressing up in costumes and performing wacky antics in exchange for food and drink, and eventually trick-or-treating became a traditional part of Halloween. WA
“All great things must first wear terrifying and monstrous masks, in order to inscribe themselves on the hearts of humanity.” Nietzsche