Summary: Abraham and David justified by faith
This chapter is pivotal in establishing that justification is by God’s grace through faith alone. Verses 1-8 demonstrate that justification is a gift and cannot be earned by works. Verses 9-12 argue that since Abraham was justified before he went circumcised, circumcision is not a basis of justification. Verse 13-17 proves that since Abraham was justified hundreds of years before the Mosaic Law, then justification cannot be based on the Law. Verses 18-25 summarize Paul’s arguments by concluding that Abraham was justified by his faith and not by his works.
As the father of the Hebrews, Abraham (Gen 12:1; Romans 4:1 (quickview) ) features prominently in the New Testament. Here in Romans 4 (quickview)  he is recalled as an individual. Elsewhere he represents the entire people of Israel, and especially those who have placed faith in God (Romans 9:7 (quickview) 11:1; Gal 3:6-9). Indeed Abraham’s faith is what makes him so important to the NT writers. God made important promises to him and his descendants, Isaac, Jacob, and Jacob’s twelve sons-promises that God repeated throughout Israel’s history. Abraham is remembered as the man who believed that God would do what He said He would do (Rom 4:3)-a remarkable thing when we consider that at the time of the promises, Abraham had very little evidence that God would follow through, certainly far less than the NT writers or we who live today. One of those most important promises was that God would send a Messiah, an “Anointed One.” Jesus claimed to be that messiah. The central question of the NT becomes, Do we believe that? Do we take Jesus at His word? Do we accept His claim and his implications? Abraham believed God; do we? Another important question raised by the coming of Jesus was, What happens to Israel? Even though many Jews believed Jesus’ claims and followed Him, by and large the nation rejected Him. What did that mean for the promises of God? Paul deals with these issues in chapters 9-11.
The comparison between Romans 4 (quickview)  and Galatians 3:6-14 (quickview)  is surely an important discussion for us to have as we open here. The appeal to the example of Abraham is briefer in Galatians and cites Scripture less extensively. Romans associates Abraham and Sarah with an argument about life from the dead by means of divine miracle, as further illustrated by the resurrection of Jesus while Galatians has an argument about the cross connected with the blessing, of Abraham being extended to Gentiles in and through Jesus. Yet in both arguments what we see clearly is the issue of priority who came first: the promise to the one who believed or the action on the basis of a work of the Law, namely circumcision is important.
In Galatians Paul argues against a temptation by the audience to get themselves circumcised and keep the Law. In Romans Paul is trying to get the audience to place more value on their Jewish inheritance and on the fact that Abraham is the father of all who believe, and he is trying to undercut the boasting and ethnic and cultural arrogance of Roman Gentiles. The lever of egoism is the fact that all have sinned and are equally saved by grace through faith. Now we discover clearly that both Jew and Gentile are in debt of Abraham the Jew, exemplar of what true faith is all about.