One night, after Gary tucks his son into bed, he hears mumbling coming from his son's room. he sees what the mumbling is and he sees that his son is praying. he overhears his prayer and he hears his son saying
" God, I want my grandpa to die tomorrow."
Sure enough, the next day, the boy's grandpa dies.
The next night, Gary hears his son praying again and this time his son says,
"I want my grandma to die tomorrow."
Sure enough, his grandma dies the next day. The next night, Gary goes up to his son's room again, scared out of his mind, and hears his son ask god to kill his mother. His mom dies the next day and, again, Gary hears his son praying.
"I want my dad to die", his son says.
That night, Gary is scared shitless. He wakes up the next morning alive and breathes a sigh of relief. Then, when he goes to get the mail, the mailman is dead.