Whoever wants to be a leader should educate himself before educating others. Before preaching to others he should first practice himself. Whoever educates himself and improves his own morals is superior to the man who tries to teach and train others.- Ali (a.s.)
This should be practiced by everyone. This quote does not only mean what it's trying to say, if you read between the lines you'll realise that it is also saying if one wants to be something, one has to be that thing full-heartedly, else you'll only make a fool out of yourself.