well doing. Superficially this verse seems to suggest that by “patient continuance in well doing,” one could obtain eternal life, without regard to one's relation to Christ. While this may be true hypothetically, the apostle goes on in the next chapter to explain that “there is none righteous, no not one” (Romans 3:10). Nevertheless anyone can receive imputed righteousness through Jesus Christ, simply by faith in Him (Romans 3:25-26).

the Jew first. The Jews, as God's chosen people, were given the first opportunity to hear the gospel, and Paul always sought to apply this principle. By the same token, they were to receive the first and most severe judgment, because of the greater light they had received (Luke 12:47, 48) when they rejected the gospel.

respect of persons. This important principle is stressed repeatedly in Scripture—first in Leviticus 19:15, last in 1 Peter 1:17, plus about eleven other times in words like these.

without law. Even though God had a chosen nation, “there is no respect of persons with God” (Romans 2:11). Since all have sinned, both Jews and Gentiles, all are under condemnation. The Jews had knowledge of God's written law and had covenanted to keep the law, so they must be judged by the law, for “by the law is the knowledge of sin” (Romans 3:20). But God has written at least the intuitive knowledge of His law internally in the human conscience (Romans 2:15), and no Gentile has been able to live up even to this knowledge. Furthermore, they have ample evidence of God in the external creation, so that they are “without excuse” (Romans 1:20). “Inexcusable” in Romans 2:1, is the same word (anapologetos) in the Greek.

called a Jew. Even though the epistle was addressed specifically to the Christian believers at Rome (Romans 1:7), Paul has constructed it as a long doctrinal and apologetic tract, which could be used both to convert unbelievers (whether Jew or Gentile) and also to instruct believers in the basic doctrinal truths and practical consequences of their faith. In this particular section, he is primarily addressing non-Christians, especially Jews, while keeping in mind that both God-fearing Gentiles and pagan Gentiles, as well as Christian believers, might well be reading it or hearing it. However, He is immediately showing the self-righteous Jews, boasting in their status as God's chosen people, that just being a Jew is not sufficient for salvation.

circumcision verily profiteth. Circumcision was the original sign of God's covenant as given to Abraham (Genesis 17:9-14) and confirmed again through Moses specifically to the children of Israel (Leviticus 12:1-3). As a seal and symbol of the covenant, circumcision was profitable, reminding all Israelite men that they and their sons were supposed to be separated unto God, keeping and obeying His law, as given to them through Moses on Mount Sinai. But if they broke the law (and thus the covenant—note Exodus 19:3-8), then the mere fact that they had been circumcised would count for nothing. They would be the same as though they were uncircumcised Gentiles. In fact, it is “circumcision ... of the heart” (Romans 2:29) that really counts with God, indicating the separation of the whole person to God.