“The reward for doing right is mostly an internal phenomenon: self-respect, dignity (self-worth), integrity, and self-esteem.”  by Dr. Laura Schlessinger.

What this quote means is that when you do what is right you always get something back. When you do good things in your life you always get a reward back. It may not be a gift or anything physical. But you still get the feeling that you did the right thing. That feeling no one can take it away because you know you did the right thing. And that feeling is the most valuable feeling that you could have. Doing what is right is a great feeling. This is why you you have to do what is right because if you do the wrong  you get the opposite. If you do the wrong you will have consequences instead of rewards.