Sometimes people take advantage of others, or circumstance alone is responsible for inflicting pain on someone. People don't like this. This is fairness. Call it what you will. Justice is how try to impose this idea on their world.
Morality is too relative.
Too dependent on whom. It is created by people. Maybe I'll try to refine this later, but not now. Well, love is still the important thing. Try to act in accordance with your love, however it be manifested.