I think the Alt was a purgatory, but the Island timeline was defiantly real and everything that happened on the island was real. and Ben didn't go into the church ( heaven ) because he doesn't belong there, he is going to hell. Jack died at the end.. everyone else didn't though they died much later on

Ok so everything that happened after the plane crash in PILOT was real, they all had those experiences on the island and they were all alive.

Jacob and MIB were important and did exist because they were essential to the island and the storyline...BUTTT

when a character dies they enter the Alt Timeline and wait / go about what thee believe to be their lives until they regain the memories from their Lives when they were alive, the 815'ers could not move on until everyone regained their memories and they were all together

I.E the whole together theme since the beginning

so jack dies, but is the last to regain his memories, Hurly dies much later than jack as you can tell because he is the new leader of the island, and what gave this away was when he said to ben "you were a great number two" and ben replies " you were a great number one" so for all we know he could have ruled for a long time and died much later, and so could have the other losties

maybe they all died at different times, they got off the island on the plane maybe kate, sawyer, chesty, richard... died of old age or something, who knows, but the point is they all have to be together in the alt and remember when they died to move on and also their previous memories. there's my take let me know what you guys think. Shoot it down, or back it up.