Oh, sorry, we're talking about Supernatural. So what else is new.
So anyway. John told Dean that he had to save Sam, and if he couldn't save him, he'd have to kill him.
Neither Sam nor Dean knows what John knew about the demon and his plans. Sam assumes it means he will "go dark side" and is always waiting for that to happen.
I think Dean, typically, has made no assumption or judgment.
But here's what they don't realize:
John did not know Sam. And he did not know SamsndDean.
Sam spent his whole life rebelling, in a variety of ways, against his upbringing and the inevitability of becoming a hunter. He was very young when he left for Stanford. He didn't "grow up," really, until after Jess died and he and Dean started The Road Trip That Never Ends. So John did not have any chance to get to know his son as an adult. And he barely got a chance to see the way the brothers operate together as adults. As partners.
So what's my point?
John was wrong.
Sammy won't--indeed, he can't go dark side. This may be because the demon, in marking him, set off a series of events that did not happen in any other family, with any other marked child. The demon has not influenced Sam's dreams or waking moments the way he influenced Anson and the last guy who was killed by Gordon (Scott? I can't remember his name). And Sam, by nature and by nurture, is a compassionate, courageous, strong man who had and has something no one else did or does: Dean.
I started thinking about this because I just cannot see the essence of Sam being anything but good. If something were to make him change that significantly, it would have been Jessica's murder compounded by his father's death. He would have been able to kill his father to banish the YED, and after his father made the trade to save Dean, he would have hardened himself. But he didn't. Men who can avoid that shell we often create to protect ourselves from further pain do not save vegetarian vampires or call the police instead of killing the man who tried to kill him. He's far too GOOD to "turn" evil.
Now, of course there are scenarios that work around that. We saw it with his possession, and the possibility with the werewolf. Madison could have easily bitten him and turned him into one. But those are NOT SAM, and the way the writers have progressed this storyline (Anson chose to kill, Scott was on his way), it's distinctly different from what the demon seems to intend.
With only five episodes left this season, we're very close to the answer. I, for one, can't wait.
On another note...
Sera Gamble gave an interview recently where she was asked about the reality of John being dead. She said he's not only dead, he's burning in hell.
Demons have said that twice (Crossroad Blues and Born Under a Bad Sign). I didn't believe them, given their propensity for lying and knowing exactly how to hurt their victims emotionally as well as physically. But Gamble's comment seems pretty conclusive, and it makes me ask why?
We don't know as much about John as we do about the boys, of course. But what we do know doesn't seem, on the surface, to justify hell. Or Hell.
He appeared to be a good father before Mary's death. He wasn't a very good one afterwards, but he wasn't abusive and even his worst actions--leaving them alone at times, teaching them to kill evil--don't seem to bad enough for Hell (though I admit what is "bad enough" is a very personal and widely variable thing).
On the surface, his role as a hunter seems straightforward enough. He hunts evil. By doing that, shouldn't he be worth a place in heaven? Or at least a nice suite in purgatory? Every single episode starts with Dean's voicing of John's legacy: "Dad wants us to continue where he left off...saving people...hunting things...the family business." But...what if that's not John's legacy? What if that's just Dean's interpretation of it? And what if, without Sam, Dean would have been destined to join his father?
Sam sees gray everywhere. He has no hesitation about killing evil and banishing the bad. But he doesn't like collateral damage. Ends don't justify means. Dean didn't think like that before Sam's influence. Evil was evil, and they kill it. End of story. Dean was always Dad's Little Soldier, so he's more black-and-white because of his father.
Now the question is, what did John do as a hunter that we haven't seen? Dean sees him as a hero. But we've heard tales of poor judgment in the name of getting the bad guy, and he seemed to alienate an awful lot of people. So it makes me ask:
Was John less like Dean and Sam and more like...Gordon?
ETA: My brilliant friend Megan said this:
"...maybe it's like a prison type thing. He traded his place on earth for the demon's in Hell in order to save his son, maybe? And it has nothing to do, really, with his soul, but rather was the bargain he made to save Dean's life."
Isn't she smart? :)