I think Jack is Jacob (future/past timelines) and in the alternate time lines he is also Locke's constant. The reason why Locke dies in the real world is that he is unable to get hold of Jack while traveling of the island.
Jack is guilty of the fact that he was not there for Locke and thus he died. Jack is the one who always needs to help and in this case he was not able to help Locke and thus the remorse/drinking/drugs. I think Ben knows a bit of this but cant tell Locke/Jack (It is their choice to realize who they are and only time can help them with it.)
As the series goes on, they will both know that the island is more about them than anyone else.. If you want to believe I think Jack is the chosen one in Jacob's role. Jack's father probably let Dharma use him for time travel experimentation. Also, in the end I think it will only be Jack left with no one else and the island will truly be LOST!!! And all of this will keep repeating in Jack/Jacob's imagination.
Theory by Gaming
Jack is guilty of the fact that he was not there for Locke and thus he died. Jack is the one who always needs to help and in this case he was not able to help Locke and thus the remorse/drinking/drugs. I think Ben knows a bit of this but cant tell Locke/Jack (It is their choice to realize who they are and only time can help them with it.)
As the series goes on, they will both know that the island is more about them than anyone else.. If you want to believe I think Jack is the chosen one in Jacob's role. Jack's father probably let Dharma use him for time travel experimentation. Also, in the end I think it will only be Jack left with no one else and the island will truly be LOST!!! And all of this will keep repeating in Jack/Jacob's imagination.
Theory by Gaming
