Every year, we get questions about where Halloween came from. And every year, I look to Father F. X. Weiser's invaluable guide, The Holyday Book (1956), for the answer.
"Halloween traditions have never been connected with Christian religious celebrations of any kind. Although the name is taken from a great Christian feast [Halloween = Allhallows' Eve = All Saints Eve], it has nothing in common with the feast of All saints, and is, isntead, a tradition of pre-Christian times that has retained its original character in form and meaning.
"Halloween customs are traced back to the ancient Druids... who belived that during the night of November 1 demons, witches, and evil spirits roamed the earth in wild and furious gambols of joy to greet the arrival of 'their season' -- the long nights and early dark of the winter months. They had their fun with the poor mortals that night, frightening, harming them, and playing all kinds of mean tricks. The only way, it seemed, for poor humans to escape the persecution of the demons was to offer them things they liked, esepcially dainty food and sweets. Or, to escape the fury of these horrible creatures, a human could disguise himself as one of them and join in their roaming. In this way they would take him for one of their own and he would not be bothered."
It gives new meaning to the words "trick or treat," doesn't it!
Happy Halloween.