The goal in life is to look for the good in everything we undergo. The simple fact that we are alive, and able to experience the difficult times that will occur in everyone s life, is wonderful when compared to the alternative. There are those who sometimes feel that they would rather be dead, than continue within the series of seemingly endless emotionally painful events that their existence entails. If your final reward is inevitable, there is no suffering that can be seen as endless, and no reason to forego any joy that may have occurred in the interim. Life can never be seen as perpetual happiness, because everything is subject to your perspective.
Life is contrast, and happiness exists only because unhappiness does as well.
To know that one is free from pain, one must know what it is to feel pain. Naturally, everyone wants to experience more good events in life, than bad. This is where the ancient adage do unto others as you would have them do unto you applies to your interaction with others. This social contract is one of the behavioural codes that is a part of our gregarious nature, and enables us to function as a society. Your perception of the world is shaped by the actions of the people around you, and your conduct influences how other people experience their lives.