It only ends once by Supernerd

MIB: Still trying to prove me wrong, aren't you?
JACOB: You are wrong.
MIB: Am I? They come. They fight. They destroy. They corrupt. It always ends the same.
JACOB: It only ends once. Anything that happens before that is just progress.

Now read this:

Locke: What do you suppose is in that cocoon, Charlie?
Charlie: I don't know. A - a - a butterfly, I guess.
Locke: No, it's much more beautiful than that. That's a moth cocoon. It's ironic - butterflies get all the attention, but moths, they spin silk. They're stronger. They're faster.
Charlie: That's wonderful, but...
Locke: You see this little hole? This moth's just about to emerge. It's in there right now, struggling. It's digging it's way through the thick hide of the cocoon. Now, I could help it - take my knife, gently widen the opening, and the moth would be free - but it would be too weak to survive. Struggle is nature's way of strengthening it. Now this is the second time you've asked me for your drugs back... ask me again, and it's yours.

Now let's make a connection.

It only ends once-the moth escaping the cacoon
Anything before that is just progress-the moth struggling

We can make the same connection with other conversations and items in LOST such as Jacob's weaving. Also Dead is Dead, which goes with it only ends once.

I'm now going to offer two theories relating to this.

1.So all the struggling that everyone on the island is going through is just progress. Flocke's deals is like cutting open the cocoon. And once you let Flocke open the cocoon, you can't go back, it has already ended. It only ends once. This happened to Sayid.

2.The island is a cocoon that MIB the moth cannot escape. The Losties can cut the cocoon and Flocke would escape. It only ends once and MIB would be free.

I personally believe that the truth is a combination of the two.

Choose for yourself. You can add more to my theory in the comments. I didn't work out all of the details. I just put down the big picture stuff. If you have more examples of "It only ends once", or the whole moth thing, post in the comments section or in your own theory.

Thanks for reading.☺ (It's a smiley face if it's too small to see ☺☻☺)