Candle is a noble thing. It spoils itself to give light to others. It indirectly mention that we must give light to others life, i.e we must share our knowledge and known things with others to enlighten their knowledge, while sharing our knowledge the things are spread out to others and we will get happiness of teaching others about a new thing.
Some of our friends use us like candle, i.e they will get our help whenever they want by doing this kind of help, we may face some unwanted problems too. Anyway, we must get satisfaction with our help and we are the main person who helped our friend to solve their problem, this kind of helps are compared with candle, because a candle lost its life to give brightness to others and remove the darkness, likewise we give light to our friends life by solving their problem and facing some unwanted things due to our helping nature. A person who is living in this sort is surely a noble person like the candle. Be like a candle and live for others sake.