It was revealed in the most recent episode that the island acts as a cork, to entrap evil and make sure it doesn’t escape. It was also eluded that Jacob, as protector of the island, acts as sort of a warden for MIB, who is imprisoned.
Lost has shown significant importance to the islands electromagnetism since Season 1, and the black smoke cracks and has flashes of light, almost like it was electrically charged. What if something happened to MIB when he was a child, that someone tied him in to the electromagnetism on the island. If he leaves the island, the imbalance or release of that electromagnetism would destroy the earth, which is the reason he is being imprisoned.
As children, after the incident occurred that created the black smoke/MIB, rules were put in place (possibly by MIB’s mom) that MIB could leave the island and go home (essentially allow his spirit to move on) if all of Jacob’s allotted candidates failed to prove the worthiness of man. The candidates and all the island inhabitants were given fresh slates when the arrived, and if one proved worthy, willing to sacrifice their desires for the good of the island and mankind, then MIB would remain trapped, as mankind would deserve to live. But if all the island inhabitants were corrupt, and not one candidate remained, including Jacob, then MIB could leave but by doing so the electromagnetism would be released, which would destroy the Earth. When Hurley, “we’ll all go to hell” maybe he was referring to the fact that the release of the electromagnetism would cause the platelets to shift, causing earthquakes, volcanoes, etc… that would literally cause people to go under. ! Maybe I’m going out on a limn on that one, but I still believe the rest will hold true, that this was a process which allowed man to prove their worthiness, and if they failed, then MIB would have his way, and would be allowed to pass on.
Thoughts?