Though he survives in the final version of the pilot, the writers decided halfway through production of the first season that John did have to die, as they believed his separation from his sons "split the show" by having him away "doing more interesting things than the boys are doing." Kripke also felt that John kept ...

Mary Makes A Deal With A Demon\n\n The demon, Azazel, became fascinated with Mary and later killed both her parents. After also killing John, Azazel promised to resurrect him in exchange for permission to enter Mary's house in 10 years. Mary agreed, got engaged to John, and swore off hunting for good.