You are right. Doing good has nothing to do with the bible, but the bible does teach us how we should live our lives in order to live a happy life and that also includes doing good for others, since most people are only living lives for themselves and they don't do anything good for others. A lot of people, especially in today's world are selfish and too busy to help others. They have no time for others. But the bible says, we are supposed to be fruiteful, not busy.