'...self-interest is not selfishness. Everyone knows that to seek gain by means of someone else's loss is wrong-headed. But if you seek to be rewarded by enriching someone, that is not selfish. Your reward for their enrichment is not selfish on your part, even though your reward for doing it is your self-interest. Rewards are a big deal in God's economy. You can't even come close to God unless you believe that he rewards: "And without faith it is impossible to please him, for whoever would draw near to God must believe that he exists and that he rewards those who seek him (Heb.11:6).'
Sam Crabtree, Practicing Affirmation, p.48.