The biggest disappointment Christians have is when they die, meet Jesus, and he tells them they have to reincarnate again, they will not be in heaven.
They do earn good merit for their faith, and Jesus will lead them to a situation where they can work off debts from previous lives, rather than just have faith alone.
Hopefully they will make good progress on their souls evolution to freedom from rebirth and reuniting with Christ.
There is no reincarnation. That is yet another lie used by Satan to further enslave humanity.