So, did anyone truly think that LOST would end with answers to every island mystery?
I think the ending leaves several things open to interpretation (and I always imagined LOST would end with some ambiguity. I mean, have you watched the show?). But the last episode, aptly titled "The End," was largely a spiritual journey. Indeed, it explained the entire show as a spiritual journey.
Good And Bad
The bad: LOST didn't quite "play fair" for six seasons, now did it? By introducing so many "important" mysteries, only a scant few had any real significance. Walt's powers. The electro-magnetic energy. The four-toed statue. The "sickness." Why babies couldn't be born. What happened to Claire's hair. None of those burning questions ever truly got answered. (OK, Claire's hair was more unnerving than demanding-to-be-answered)
The good: In the end (or, in "The End"), a lot of those questions didn't really matter. The last half hour was layered with so many philosophical and spiritual themes, it rendered every scientific question moot.
In the first episode of season six, when Jack is on the plane "home" into the "sideways universe," he clutches his armchair as they hit some turbulence. Rose turns to him and says, "You can let go now." It's a line of dialogue echoed by Christian Shephard in the second-to-last scene, and damn, if that isn't the whole theme of the show.
There's some post-finale discussion about "what's real" and what's not. Was the sideways universe purgatory? Was the island their "real life"? Or was the island a stopover before purgatory? Or was the island a last flash before death? When did everyone die? In the plane crash? On the island? Or, to totally trip your mind, was there even a plane?
I can only offer my own interpretation. And the lovely thing about the finale, is that you can have a different way to see it, and we can both be right. As the multiple religious ornaments in the funeral parlor indicate, we all have a different way of seeing the spiritual side of things.
I think LOST was largely from Jack Shephard's point of view. From the very first frame of the first episode, we see his eye open. It's also the closing shot of the entire series. I believe everyone died on the plane crash of 2004. (If indeed it was a plane, or just a metaphor for a journey into "the other side" after death).
Life, Death, Rebirth
The island, as I see it, is a mystical well of souls. A magical place for the dead to sort out their lives. To reconcile the things they need to reconcile. To lay them to rest. And once they complete that journey, they can "move on." The show has dealt with the themes of redemption and rebirth, so this fits perfectly with that notion. That cave light was, after all, "life, death, rebirth," we are told.
Christian's words in the second-to-last scene give many clues to interpret as you will. When Jack asks, "Are you real?" He answers, "I sure hope so. Yeah, I'm real. You're real. Everything that ever happened to you is real. All the people in the church. They're real, too."
Some fans want (or need) the island to be "real", in the sense that it's "not the afterlife." Perhaps Jacob, a force of good, gathered them on the island as a final test before their physical deaths. But whether you view the island as a mystical stopover - or an actual physical island that exists in the Pacific, it's irrelevant. It's "real" either way. And it's only our limited earthly perceptions that might view "afterlife" as "not real." Follow?
Nobody Goes It Alone
Christian goes on to say, "Nobody does it all alone, Jack. You needed them, and they needed you. To remember. And let go." (Hey, Rose said that, too!)
From this, I see the island as a mystical stopover in the afterlife created by the inhabitants. Something akin to a shared mass delusion, if you will. And although we are seeing the show from Jack's point of view, we also see Sawyer's journey, Kate's journey, Hurley's journey, etc. Because they all needed each other to reconcile their lives and make peace.
Now, some island residents can be "props characters" created by the island (and/or its inhabitants). It would explain why the Dhamrma Initiative characters didn't have to reconcile their issues. Or for characters like Shannon or Boone, the island may have been only part of their journey (and perhaps we didn't see some other parts). Or for characters like Nicki and Paulo, maybe they never reconciled what they needed to. Still concerned with their own selfish pursuits, they were incapable of redemption. For them, it may be an endless loop, or perhaps they went to "that other place" people go when they aren't good people. The place with pitchforks and heating problems.
Jacob and the Man In Black, I believe, are constructs created by the inhabitants (largely Jack, who was raised a Christian, but had little faith). Although Jacob and Man In Black evoke some familiar biblical characters (Cain and Abel, Jacob and Esau, God and Satan), Jack created his "own" version of God and Satan. So Jacob and Man In Black are a gestalt of those biblical characters swimming in Jack's head; From Jack's upbringing, he remembers the facts even if he doesn't believe in the faith. Also note that other characters in search of their own redemption may see them differently to suit their own journey. Richard Alpert, a man of faith, saw them as God and Satan. Perhaps others might see them as Yin and Yang, opposite sides in balance.
The flashbacks of seasons one through three, I see as their "real lives" more or less. It was everything they needed to reconcile and atone for. Things that still haunted them. Things they regretted in life. Some of those mystical elements in those flashbacks (Jacob's visits, Hurley's cursed numbers) can be seen as either "divine intervention" or a colored view of your own history that suits your personal spiritual journey on the island. When many of them did reconcile their issues, they moved up a "level" to "sideways universe." When Jin and Sun truly saw each others' true selves, they "died." When Sayid did enough to make up for his past by sacrificing his own life. He "died." And so on.
"Sideways Universe," I didn't see as purgatory (I know some viewers did). To use a Christian belief, it was more like the Gates of Heaven. Here, you got a taste of the other side. A reward for redemption. It's the final step before "heaven". Enlightenment. Nirvana. Call it what you will. (Pick a symbol or belief system from that room in the funeral home.) The ideas of "levels" in the journey is common in many Eastern religions. (And Jack did get that Asian tattoo in that Bai Ling episode everyone hated.) At any rate, "sideways universe" is where you finally "let go."
It's also interesting to note who is in the church. These are all characters who made some sort of amends on the island. No sign of evil eye-patch guy, or Nicki and Paulo. And even Ben isn't ready yet (probably not yet feeling worthy, even after years of off-screen repentance as Hugo's Island Keeper). But Ben's journey was always one of humility, wasn't it?
As for Jack, his journey was from cold, hard reason to embracing his faith. His inner conflicts always involved his obsession to "fix" things that often couldn't be fixed (the guy couldn't even "see" his own death, but unconsciously no doubt, thought he could "fix" that, too). In the beginning of season six, in the wake of the bomb, he's almost resolved himself to faith. It's his last step as the Island Protector that earns him a final redemption. Further proof it's all Jack's story? The series evolved from somewhat logic based (scientific experiments and electromagnetic energy) to full-frontal mystical (golden light and healing waters). So the backdrop of the island kinda mirrored Jack's metaphysical journey all six seasons.
At least, that's how I see it.
There will be a lot a naysayers that will be annoyed that many questions weren't answered. I think you have to go back and look at those "mysteries" in a new light - as symbols and themes, not actual science that can be broken down into mathematical equations. You could see the smoke monster as "guilt." Or the mysterious numbers as "adversity." Or the Dharma Initiative as "the man." Or the Others as "distrust."
In short, if you are still annoyed that they didn’t answer every “reason-related” question, you’re still “season one unenlightened Jack. “ If you embrace the spiritual ending fully, you are “season six enlightened Jack.” At least, that’s what the show is telling us. ; )
Or as Rose might say, "You can let go now."