When someone does you a good deed, you must never forget it. You must look out for the opportunity to do a good deed to that person. If you do not get that opportunity then you must pass on the good deed to someone else. It is quite a strange fact of life, that a good deed done to another always bring some kind of reward to the person who has done the good deed. Hence you must always return good with good.
People go throughout their day encountering random acts of kindness in many various ways. Whether it is simply acknowledging someone who walks right past you by saying hello and smiling, or just holding the door open for someone entering behind you, kindness is everywhere. However, there are also certain people who do not openly express their kindness to others. For example, take the driver who suddenly and abruptly cuts you off when changing lanes; even though you would like to tailgate him all the way to his house to make him angry, “one good turn, deserves another.” Let the driver go, and carry on with your day. In return, the driver may feel sorry for his or her actions and perhaps one day, when you extremely need to craft a massive 5 lane change manoeuvre, someone will let you go.
The Messenger of Allah, peace and blessings be upon him has always preached the philosophy “Always be kind to others” to his Ummah. Once he said, “He who is deprived of kindness is deprived of goodness.” Even if others may not behave in a benevolent manner towards you, always respond with kindness.
A favour in return for a favour
That is what any man will do
A favour in return for an evil
That is what a manly man will do
Sometimes, people may be astonished by your response and feel obliged to do the same to others. In addition to it, a touch of satisfaction lies in performing good to others.