Again and again god teaches us to keep eternal perspective.  "Masters, give your bondservants what is just and fair, knowing that you also have a master in heaven" (Colossians 4:1).
The principle holds true for all relationships.  Bosses, pay your employees what is just and fair, knowing you also have a boss in heaven.  Parents give to your children what is just and fair knowing that you also have a father in heaven.  Teacher give to your students what is just and fair knowing that you also have a teacher in heaven.
Our behavior toward others should always be tempered by the fact that God is watching.