" Only those live who do good." 

Count Leo Tolstoy 

What this is saying is that only the people that do good live and the people that do bad don't. This is saying that bad people don't really live that long because of all the bad things they do, and all the problems they have. The people that do good live because they don't really do anything bad or wrong they might do wrong things at point but it isn't a major thing that will make them not live. Like the people that do bad may die because they were either doing bad stuff like gang banging, hurting other people, making other people suffer and ruining their lives. Therefore those bad people have consequences whether other people go after them and kill them or they go to jail or they end up suiciding themselves. If you live while doing bad things what's the point on living if your doing bad things and being a bad person. If you do good things and be a good person then you will live because you're not harming or hurting anyone.