A "reward" in the Bible represents something that brings people together, or brings spiritual states together, and binds them. In the Bible, of course -- especially the New Testament -- we're told repeatedly to do what is good and right "without thought of reward." That's because removing the idea of a natural reward lets us be aware of spiritual rewards, which are actually intrinsic to the good that's being done. On a relatively low level, we feel delight in doing something nice and useful for someone else; that delight is a reward. The love that can exist between partners in a committed, loving marriage is a reward. The delight we feel when we truly want what is good and know how to create it is a reward. And ultimately, our conjunction with the Lord and the delight of His love and salvation is the deepest reward of all. These are the things meant when the Bible speaks of "rewards.