Philippians 2:3 states, "...with humility of mind regard one another as more important than yourselves." But when others seem less capable than you, how can you do? It doesn't mean you must regard them more competent than yourselves. Rather, it implies you should accept them as they are and have a hope for his renewal. Concerning someone who is quick-tempered and sometimes lying, you should try to find his good points and believe he'll change into a great person. If you stay away from him due to his shortcomings, it may be your arrogance. Only when you accept and embrace others with humility can you lead many more people to the Lord.