So, for all of our enlightenment....
From The American Catholic Truth Society:
Origins of Halloween
Originally, before it was a Christian holy day, October 31st was a Celtic celebration wherein the Celts believed their departed family and friends returned to their homes to eat and drink. Being the harvest time, food was more plentiful, and some was left out on this evening for this purpose.
Trick or Treat and Costumes
In England this tradition began on "Mischief Day" where kids would dress like goblins, ghosts, witches, etc. to be scary, then knocking at the doors of their neighbors, they would demand treats, or they'd do some sort or michievious
"trick" on them.
Several English localities participated in "Punky Night" wherein the children would sing in the streets, carrying "punkies" (Halloween lanterns, a carved out gord or small pumpkin with a candle in it). It is believed this custom started with the women of a local community walked to a nearby fair, using the "punkies" to light their way - and their purpose was to go find their drunken husbands and drag them home.
Another story involves "Jack" who liked to drink a lot and also was a wagerer. One night, some say Halloween night, Jack was drinking in the bar, and came close to falling into the hands of the Devil. The Devil sat there with him, and Jack talked him into buying him one more drink in exchange for his soul. The Devil agreed, and turned himself into some coins, enough to buy that one more drink. Jack tricked the Devil, and put the coins in his pocket, where he also had a crucifix. By the power of the crucifix, the Devil could not change himself back - and Jack would not release him until the Devil promised not to try again for Jack's soul for at least ten years. The Devil agreed, and was set free. Ten years later, the Devil, still mad over being tricked the first time, came back after Jack. Jack seeing the Devil thought quickly, and came under an apple tree. Jack asked, if you could just get me an apple, I will go with you. The Devil agreed, climbed into the tree and Jack quickly got out his knife and carved a cross into the tree - and the Devil was stuck in the tree. Jack made the Devil promise to never come for his soul again, or he would not remove the cross from the tree. The Devil, seeing no way out, agreed. Later, Jack died. Due to his sinful lifestyle, heaven refused him - but when he came to hell, the Devil honored his word and also refused him. Jack wondered where he should go, and the Devil sent him back to earth to wander the nights - and to have some light, the Devil gave him an ember from hell and placed it into a turnip to be used as a lantern - and hence Jack and his lantern wander the earth, awaiting the final judgment.
If we think of "Jack" when we see the Jack-O-Lantern, maybe we'll try to live a better life so that we are not turned away at heaven's gate!