What does Romans 4:1 mean?

At the end of Romans chapter 3, Paul revealed that human beings can be justified by God apart from the law. In fact, he made clear that the only way to be justified—to have our sins paid for, so we can be seen as righteous before God—is through faith in Christ. Without that, each of us will be judged for our own goodness and be found sinful and deserving of God's angry judgment. Paul insisted that this was true of both Jews and Gentiles (Romans 3:21–26).

Now Paul begins to answer an obvious question: what, then, was the point of God's special relationship with Abraham and Israel? Was the law pointless? Paul ended Romans 3 by reassuring his readers that his teaching about faith in Christ upholds the law. He does not mean to do away with Israel's history. He restates the question in this verse. What was gained by Abraham? Paul includes himself with the Jewish people in describing Abraham as their ancestor "according to the flesh." In other words, all Jewish people, including Paul, were descended from "Father Abraham."

Paul will show in Romans chapter 4 that both Abraham's and David's relationships with God were by faith, and that their examples point to faith in Christ as the way to become right before God.