Romans 2:21

18 if you know his will and approve of what is superior because you are instructed by the law; 19 if you are convinced that you are a guide for the blind, a light for those who are in the dark, 20 an instructor of the foolish, a teacher of little children, because you have in the law the embodiment of knowledge and truth— 21 you, then, who teach others, do you not teach yourself? You who preach against stealing, do you steal? 22 You who say that people should not commit adultery, do you commit adultery? You who abhor idols, do you rob temples? 23 You who boast in the law, do you dishonor God by breaking the law? 24 As it is written: “God’s name is blasphemed among the Gentiles because of you.”