Why they went back

Is one of the big themes in Lost going to be redemption - especially Ben's? if so, that explains why the adult members of the O6 had to return.

In my "whatever hasn't happened yet, hasn't happened" theory, I propose that Sayid shooting Ben leads him to the hands of Richard Alpert and the Others. I predict that his healing in the temple will awaken in the 2007 Ben a new sense of spirituality and understanding of the Island - something missing until the shooting and trip to the temple.

If this is the case, the returning members of the O6 played a role in Ben's transformation and redemption (as well as their own possibly).

Sayid had to return to shoot young Ben.

As odd as this sounds, Jack had to return to NOT save his life - leaving to only option to go to the Others

Kate had to deliver Ben to the Others

Hurley - I haven't figured him out yet.

But for the above three, their actions upon returning may offer them some redemption as well.

Kate unselfishly does something to help a young boy, atoning for her selfishly taking Aaron away from his real family.

Jack realizes that he can't save everyone and that sometimes he must let events take their natural course.

Sayid's shooting of Ben actually sets off a series of positive events as opposed to the assumed negative events of his past killings.

Can these, and potentially other, positive outcomes be the hidden story and legacy of the Lost island?