But if you call yourself a Jew and rely on the law and boast in God and know his will and approve what is excellent because you are instructed from the law; and if you are sure taht you yourself are a guide to the blind, a light to those who are in darkness, an instructor of the foolish, a teacher of children having in the law the embodiment of knowledge and truth-you then who teach others, do you not teach yourself? While you preach against stealing, do you steal? You who say that one must not commit adultery, do you commit adultery? (2:17-22).
What is paul establishing in in the judgment principle and also the law principles that he talks about in chapter 2?
He is directed at their beliefs vs. their behavior. They say that they believe in God. Are they abiding by their own teaching? You told us we can't do this, but you do it yourself. What makes you think that we shoudn't do it if you are? It says in verse 24:" The name of God is blasphemed among the Gentiles because of you." This shows that the Gentiles saw that the Jews teaching of the law was not matching up to their actions.
Paul supported that they were in this idea that teaching God's word is one thing and what you do with it is something completely different. The fact of the matter is that it isn't two different things. These two concepts go hand in hand with each other. Abiding by God's word is not only knowing it, but doing what it says in full capacity. You can preach it, but are you doing it?

Lord,
Please help me to live out what you are teaching me. God, I know you have a plan for everything. If it be your will, make this known to me. God, thank you for the example of paul: For his desire, and strength, that you give him. Thank you for the applications of your word.
Zeke