We don't know the truth, but we know the utility of our beliefs, and we can use this utility to make a decision .
For example:
Pascal wager:
1. I believe in God and behave accordingly. If it is not true, then my behavior brings me community of religious people. If it is true I have the Heaven
2. I don't believe in God, if it is not true I go to Hell, if is true nothings happens.
Belief that surgery is against God.
1. If it is true, then I will live longer here, then go to Hell
2. If it is not true, the I die here, but this doesn't guarantee Heaven because other deeds.
