Halloween is Celtic New Year
Early in Celtic History they had a tradition surrounding the harvest season. They considered this the beginning of their New Year. They would all gather in the center of town where they would sing and dance and pray for a good year. Everything was done by candlelight and was done until sunrise. While they were in town they had to leave all their doors and windows open and put food out for the visitors. They believed that the spirits of everyone who had lived there passed through on that night, if you closed the doors these spirits stayed and haunted you for the rest of the year. It is thought that this is where our witches and hobgoblins originated. When the Jesuits came to convert the people they realized that they would have to create a feast day to replace this one so All Hallows Eve was created. That is the eve of All Saints Day which eventually became Halloween.