One of the all-time most popular posts on this blog is my explanation of the ending of LOST. I’ve occasionally had people reach here searching specifically for “What was the ending of LOST?” and it is actually a good question. There is a sense in which an ending in the afterlife is not what we usually mean by a show’s ending. If one believes in an afterlife, then presumably all characters end up there, whether one is talking about the ending of M*A*S*H, LOST, or any other show. And if you don’t, then the fate of Henry Blake was a tragic death with nothing more following for him, and LOST’s portrayal of the idea that Jack Shepard and anyone else from the island entered some other spiritual realm might be annoyingly at odds with your worldview.
So was that the ending of LOST? If what you mean by a show’s ending is the resolution of major plotlines, then (although there were some issues of consistency along the way) the ending was Jack defeating the smoke monster, who was revealed as neither simply good or evil, but like his brother Jacob, a figure in part heroic, in part tragic, but one who, unlike Anakin Skywalker, never returned to the light side, even briefly. And the ending was the baton of care for the island being passed from Jacob to Jack and then to Hurley.
If that’s what an ending is for you, then simply ignore the flashes sideways that turned out to be flashes into an afterlife. Ignore the scenes in the church. Focus on what happened to the characters when they were alive, and set everything else aside.
And so maybe that’s the question those who strongly disliked the ending should ponder: if it bothered you that much, why didn’t the entire series bother you in quite the same way?