Jack is Desmond is Jacob by D Mac

Re-watching the 1st season I had a thought. Namely, that Jack has always done what Desmond stopped doing with Charlie. Jack stops people from dying. It may seem obvious, Jack being a doctor and all, but a major theme of the show is fate vs free will. The goal of a doctor, arguably, is to use his knowledge to stop fate(death). Jacks knowledge of medicine is just a smaller, but similar type of foresight he shares with Desmond.

Desmond can see into the future, and acts to save charlie, Jack KNOWS what is going to happen medically, and acts accordingly. The people Jack saves do die eventually. The stand out being Rose in Pilot 1. We will have to see if she lives or dies, or has been dead all along. Desmond realized, as I think Jack did later on, that the universe course corrects, and therefore stops trying to save people, and instead focuses on resetting everything.

I posit that Jack and Desmond are, or have both been, proponents of free will over fate, and have changed there ways.

With that said, I believe Jacob is the same. I believe that Jacob and MIB are two parts of the same god. And that striking a balance between fate and free will is the main purpose of these two. I also believe that the playing out of that purpose is the cause of all human suffering in the world of Lost, on and off the island.

Jacob uses whatever powers, energy or other supernatural thing to delay the fate of the oceanic survivors. This is most obvious in his touching of the losties in season 5. Jacob has also, arguably, gone against fate by bringing the black rock to the island. This makes MIB want to kill him, but he can't.

Jack is Desmond is Jacob, and Locke is MIB in the sense that he is a proponent of Fate over freewill. The losties are just chess pieces, the island a chess board and the players are Jacob and MIB.