The flash-'sideways' stuff, i.e. the almost-entirety of season six, was irrelevant to the story

What do you think makes it irrelevant?

Don't get me started on it all being Christian mythology after all.

It wasn't. The church was multidenominational.

In the sense that we were misled into thinking that it was closely connected to, or even concurrent with, immediate events on the island. It was not. Desmond didn't go there when Widmore dosed him with electromagnetism, although we were supposed to think he did. Small to large events, from the sunken island under the Oceanic flight to Juliet's dialogue while she was dying, weren't related to their apparent counterparts in the other worlds. There was a whole lot of misdirect that has left me very pissed off.

I wasn't looking for answers to every question - I don't mind that Walt's psychic abilities aren't relevant, or that we don't know what gave the numbers their power, or that we don't know who built the temple and why, or even that the light at the centre of the island is never going to be explained. But I did expect more than a deus ex machina ending that appears to have been entirely unrelated to the rest of what happened in the season. I mean, seriously? Christian telling us everyone's dead? I thought the Lost writers could do better. Or at least, could do slightly more coherent.

It wasn't. The church was multidenominational.

I saw that. But it's hard to explain purgatory and walking into the light outside of a Christian context. OK, maybe just about. But it felt very Christian imperialist to me, after many seasons of fantastic pagan temples and pantheistic imagery.

Alternate endings: [link]

'Lost' Possibly Still Airing In Parallel Dimension, Desperate Fans Report

sunken island under the Oceanic flight

Since the Sideways world was a collective construct of the Lostaways', I've decided they sunk it psychically.

Juliet's dialogue while she was dying

That was completely related to the Sideways world. When you die, you download to Sideways Purgatory. As she was dying, she got some bleed-through; her coffee line is right after the download.

Cindy's recaplet is up at TWoP, btw.

The Man in Black's name revealed!

(That's not a joke link, by the way. It's seriously his name, so don't click if you want it to remain a mystery forever.)

There was a whole lot of misdirect that has left me very pissed off.

I'm sorry you feel like it was a misdirect intended to fool the viewers, but I don't see it as a misdirect. I see it more as the episode "Enemies" on BTVS, where it seems like the Mayor found a way to make Angel into Angelus, and "Angelus" conspires with Faith against Buffy, but then it turns out that it was all a setup in the first place -- only the viewer doesn't know that from the outset. Maybe that IS a misdirect, if you assume that you the viewer have to have all the information right up front.

But I gotta say, with Lost, I have never assumed we had all the information right up front. Partly because I don't think that the creators and writers even had all the information, because I don't think they knew what they were doing for a good 4 seasons. But anyway, I don't find the sideways world a misdirect.

But, you know, everyone's going to react to it differently, and I'm sorry you're so pissed about it.

The Man in Black's name revealed!

Huh. That's as good a name as any, I suppose.