"You can not do wrong and feel                   right. It is impossible."
              ~Ezra T.Benson
  This quote is saying that if you do something that isn't okay, its not possible that you'll feel right about it . At first you might think its not a big deal but later on that wrong choice will affect you and you'll soon realize that you messed up and then you'll feel bad about it.
  For example you might think that its alright to talk back to your parents because your "taking a stand" and you want things to go your way but later on you will realize that it was wrong because after all there still your parents and want to do whats best for you.