Halloween costumes, candy, and trick or treat:
According to the book Halloween—An American Holiday, An American History, some of the Celts wore ghoulish costumes so that wandering spirits would mistake them for one of their own and leave them alone. Others offered sweets to the spirits to appease them. In medieval Europe, the Catholic clergy adopted local pagan customs and had their adherents go from house to house wearing costumes and requesting small gifts. The Bible, on the other hand, does not permit merging false religious practices with the worship of God.