>>761689
We do not pay a debt to God when we do good works. We do not indebt ourselves when we sin. The notion of "reward" and "punishment" is only one way to explain the ultimately mysterious final judgement, and in a sense it is not literally a "reward" (because the relationship of the Church with God is like that of a wife with her husband, therefore a good outcome is the result of a loving and self-sacrificial relationship, not of fulfilling a list of missions to do) nor is it literally a "punishment" (because punishment is for purification and repentance, yet those who are punished are punished eternally). Even the idea of "God punishes us" loses its stability in the Old Testament, where God says several times, especially in the prophets, that Him punishing Israel, and Israel punishing itself, are one and the same thing.
With that said, let me go back to the beginning of my point - it is not a matter of "payment" or "investment", but "relationship". We are not motivated by the incoming reward or punishment but by our love for God and His immense love for us. The "reward" or "punishment" is merely the logical consequence of going down one path or the other, like how a child who puts his hand on a stove will logically burn himself.
Incidentally, what you are talking about is a big problem of Islam - they do literally think of it as a "point" system, or as jobs to fulfill, or as debts to pay.