I believe that there is so much negativity in society nowadays. People try to fight fire with fire and that's not the way to solve problems. What the quote is saying is that you cannot put out the hate in someone's heart by hating them in your own heart. You have to take the higher road as the bigger person and put differences aside by sticking to a positive attitude and outlook on life and people. This will make living a lot more fun and peaceful not only for yourself but the people around you.