"You cannot do wrong and feel right.It is impossible." by Ezra T.Benson

I think what this quote tries to say is that when ever you do something bad you won't feel joy instead you will be thinking and tormenting yourself if it was the best choice.In the real world if you murder someone you will be thinking of what you have done and why you chose that path.In sports if you do something like an own goal or lose the ball you will be thinking of your previous mistake and most likely won't work at your full potential.It doesn't matter what your mistake may be, the only thing that matters is not to do it again.