"If your so-called friends urge you to do anything you know to be wrong, you be the one to make a stand for right, even if you stand alone. Have the moral courage to be a light others to follow." -Thomas S. Monson

This quote is saying that if you are being pressured by your friends (peer pressure) to do something and you know its wrong make a stand to the correct situation. Even if you have no one to back you up in your stand you must be brave enough to stand up, and when there are others in the same situation they can look up to you and do the same steps.