The Form. Romans 2:17-20 V.17. These verses, which take the form of a dialogue as Paul, who had been a self-righteous Jew before the Lord saved him, speak to what was a common frame of mind of Jews in relation to Gentiles. There was a lamentable disparity between the truth they knew and their practice of the truth. Boasting about having and understanding God’s law and at the same time breaking the law by the way they lived brought the strongest condemnation on them. This attitude toward the law reinforces the truth that all the law can do for us is to condemn us because of our sin.
V.18. There were in the day of the writing of this letter, those who were Jews and as such were greatly privileged to have the law. A Jewish teacher’s knowledge of the will of God allowed him to test the teaching and "approve" the things that were wrong and the things that were right. He took the place of being a guide, a light, a corrector of those who didn't know the truth of God - and a teacher. He had "the form" of a learned person, and professed to know the truth of God and God's will for others. However, the outward form and knowledge of the law and even all of the scriptures, are not what constitutes truth. Truth involves both the statement and the fact being experienced and consistently practiced.
V.19-20. The Jews in Paul’s day, considered the Gentiles to be blind as babies in moral understanding. The inconsistencies of the Jews in their conduct made their aspirations to teach the Gentiles, null and void. For those who profess to be "Christians" today, the same principle holds true. God's judgment is according to what is real, not what religious people profess or even teach. This seventh principle of God's just judgment will be applied to those who take the place of leadership in teaching the Word of God and preaching God's Gospel. These principles are given to make men awake to the truth about themselves and the false hopes they pride themselves in. These are descriptions of how God judges in order that people awaken to the truth, and not deny or ignore it.
These truths about the Gospel are also so that those ungodly people in chapter one, and the self-righteous and smugly complacent religious people in chapter two, will be awakened. The fact is, both the ungodly and self-righteous are condemned because of their sin, and the judgment of God is upon them. These condemning words are to stir them to repent and believe the Gospel.