The Jews' Failure to Keep the Law
"While you preach against stealing, do you steal? You who say that one must not commit adultery, do you commit adultery? You who abhor idols, do you rob temples? You who boast in the law dishonor God by breaking the law."
Paul opens his presentation of the gospel in Romans by explaining that it reveals a righteousness from God by faith (1:16–17). Before proving this point directly from Scripture, the Apostle first gives us a penetrating exploration of human sin to show why righteousness must be by faith alone. No first-century Jew in his audience would have contested his evaluation of the Gentiles in 1:18–32, for they were known sinners, but his condemnation of his Jewish brethren for the very same transgressions in chapter 2 is a different story. In fact, one of the biggest stumbling blocks to the gospel for ancient Jews was the idea that they, no less than rank pagans, had no claim upon the Lord. The New Testament provides ample witness to the fact that many first-century Jews believed themselves to have attained a sufficient righteousness before God by keeping the Mosaic law (Luke 18:9–14). To hear that this was not the case and, moreover, that it is not possible to follow the law of God to the extent He requires for justification hardened the hearts of the self-righteous against the gospel. The same thing happens today for all self-righteous people.
Many first-century Jews believed they could obey the law unto justification—the Lord's verdict of righteousness—although few if any of them confessed that perfection was required. Paul's great insight (building on the teaching of Jesus Himself, see Matt. 5:48) was that if we try to merit our righteousness before God through the law, we must keep the commandments flawlessly, one hundred percent of the time. This is explicit in Galatians 5:3 and implicit in his statement that only the doers of the law will be justified (Rom. 2:13). Paul knew the Jews of his day did the commandments, at least occasionally. Since today's passage tells the Jews that they break the Mosaic law, that means he viewed justification by law-keeping possible only if one never fails in his obedience to the Lord.
As upright as the Jews might have been in comparison to the pagan Gentiles, there was still sin in their camp—adultery, theft, and idolatry (vv. 21b–23). Not every Jew was guilty of acting out all of these sins to their fullest extent, but the Jewish community did include those who were willing to fall so far from God's standards. Moreover, given what Jesus says about God's commandments and their regulation even of our heart attitudes (Matt. 5:21–30), even Jews who were faithful to their spouses committed adultery in their hearts. At least in their hearts, ancient Jews—like all people today—were thieves and idolaters as well.
Coram Deo
John Calvin comments on today's passage, "We are here warned, first, not to flatter ourselves and to despise others, when we have performed only some portions of the law—and, secondly, not to glory in having outward idolatry removed, while we care not to drive away and to eradicate the impiety that lieth hid in our hearts." Our goal should always be to root out sin in our own lives first before we point it out in others and in the world.