The Island is the cage of Devil by Loxias

I think we're agreed that LOST is full of direct influences to the Bible. Just to quote one: Ben with Jack at the Lamp Post Station in LA, talking about St Thomas doubt with Jesus and stuff. We can also see that Jacob might be a direct influence to the Bible, he might be the true Jacob of the Old Testament and, if it's true, MIB must be Esau, the the eldest son of Isaac, Abraham's son.

So if we guide this path, we find out in the Book of Malachi, in the Old Testament, a quote from Yahve talking about Jacob and Esau and he says ‘Yet I have loved Jacob, but Esau I have hated, and I have turned his mountains into a wasteland and left his inheritance to the desert jackals.’ I think this is a very important point of view to judge where will go LOST on the next episodes, and why Dogen said MIB is evil incarnate.

But we forget a very important question: Why does Jacob look for a candidate? I think the own Jacob might be an archangel or a cherub that stays away the Devil (MIB) from the outside world. I think he wants to 'go home' and he's recluiting people to his cause just to spread his evil, to infect people. And that's because the Island MUST exist, without it the world can't be balanced, and the scale is tilted towards either side. So flash-sideways are just the world without the Island, without balance. They might be happier or saddest than real world, but without the Island the true path, the real path is blocked, I don't know if you understand what I'm meaning. So that's why I'm thinking that the characters, at the end, will refloat the Island, so the world will be balanced at last, and everything will back to normal.