If Karma was real 15 year old girls would not die of cancer, 10 year old boys would not be murdered in a fire fight. There would be no child abuse, nor incest with rape. Life is awful sometimes, it just is. It is up to humans to make it better.
There is no universe that blindly gives justice to humans. Only humans can apply justice to and for each other. This does not mean that we should lack faith. Sometimes believing in the goodness of people makes those people act better. Faith works, but is unreliable.