"Only those live who do good." - Count Leo Tolstoy

This quote means that if you do good being a ctr person 24/7 then you will live forever because people will remember you you and who you were. And why were you remembered. For example if you were the type of person who was nice to everyone then people will remember you as the nice person. If you were a horrible person then people will probably remember you but in a bad way. Or they would not at all. Ort you can look at it like if you were good you will be remembered as being good. If you were bad then people will not remember you they would be glad that you aren't there anymore.