[Iceman]

Right my most far fetched theory is that, Jacob summoned them all to the island to find a replacement for himself as he knows his time is up and that his enemy will find a way to kill him. Jacob knows they all have their flaws but presents them with a chance to redeem themselves. Those who can't be redeemed are finally free of their burdens and can die peacefully.....my theory leads onto that Jacob is torn between two to be his replacement Jack and Sawyer.....he see's the good and bad in both but knows that one of them will take his place in the end....

I know there's a lot of flaws in this but it just keeps coming into my head....