Predestination is one of the main Calvinist doctrines. It states that God already knows who will go to heaven and who will go to hell and that he has predestined these people for their fates.
Problems with Predestination
Predestination carries with it a lot of problems. For one, a person's actions and beliefs during life have no effect on their fate. Under predestination a person who led a completely calvinist life will still go to hell if that's what God predestined for him.
Is a person's fate completely arbitrary? If not, then how does God determine it? If so, then how does this not remove the person's free will?