Lost finale aired tonight

[Great Rumbler]

So they weren't dead? I dont understand.

Everything that happened to them on the island actually happened. It was a dream or a fantasy or purgatory or anything like that.

BUT, once they died, either on the island or much later after some of them managed to escape, they went to a purgatory where they relived their lives without Jacob's influence and where Oceanic 815 never crashed. Once they all met up again and realized where they were and what had happened to them, they left purgatory for heaven. Or whatever.