Romans 2:18-21

18if you know his will and approve of what is superior because you are instructed by the law; 19if you are convinced that you are a guide for the blind, a light for those who are in the dark, 20an instructor of the foolish, a teacher of little children, because you have in the law the embodiment of knowledge and truth— 21you, then, who teach others, do you not teach yourself? You who preach against stealing, do you steal?