One Halloween, as it happened, the time came for him to die. When the devil arrived to take his soul, Jack was lazily drinking at the pub and asked permission to finish his ale. The devil agreed, and Jack thought fast. "If you really have any power," he said slyly, "you could transform yourself into a shilling."
The devil snorted at such child’s play and instantly changed himself into a shilling. Jack grabbed the coin. He held it tight in his hand, which bore a cross-shaped scar. The power of the cross kept the devil imprisoned there, for everyone knows the devil is powerless when faced with the cross. Jack would not let the devil free until he granted him another year of life. Jack figured that would be plenty of time to repent. The devil left Jack at the pub.
The year rolled around to the next Halloween, but Jack never got around to repenting. Again the devil appeared to claim his soul, and again Jack bargained, this time challenging him to a game of dice, an offer Satan could never resist, but a game that Jack excelled at. The devil threw snake eyes—two ones—and was about to haul him off, but Jack used a pair of dice he himself had whittled. When they landed as two threes, forming the T-shape of a cross, once again the devil was powerless. Jack bargained for more time to repent.
He kept thinking he’d get around to repentance later, at the last possible minute. But the agreed-upon day arrived and death took him by surprise. The devil hadn’t showed up and Jack soon found out why not. Before he knew it Jack was in front of the pearly gates. St. Peter shook his head sadly and could not admit him, because in his whole life Jack had never performed a single selfless act. Then Jack presented himself before the gates of hell, but the devil was still seething. Satan refused to have anything to do with him.
"Where can I go?" cried Jack. "How can I see in the darkness?"
The devil tossed a burning coal into a hollow pumpkin and ordered him to wander forever with only the pumpkin to light his path. From that day to this he has been called "Jack o’ the Lantern." Sometimes he appears on Halloween!
Find other Halloween traditions' explained here. Halloween is so awesome!