1 Corinthians 9:27

But I discipline my body and bring it into subjection, lest, when I have preached to others, I myself should become disqualified.  

We have all heard the saying practice what we preach.  Which is so true when we become an example for something we need to practice in private before we take it public.  If we can’t control our temper or the words that come out of our mouth who will believe our witness.  Learning personal lessons about how to control ourselves boosts our confidence and helps us to relate to others in similar circumstance.