What does Romans 4:4 mean?

Was Abraham justified before God because he earned it by his good works or because he believed what God told him? That's the question Paul is tackling. His opponents, the Jewish religious leaders, taught that Abraham was especially good. Or, at least, that he was obedient to God's law. Abraham's works, in other words, made him acceptable to God. By their logic, then, all people wanting to be called Abraham's children must follow the same path.

Paul has disagreed, pointing to Genesis 15:6, quoted in the previous verse, to make his case. Abraham was declared righteous by God, in spite of his own personal sin, because he believed God. All of Abraham's acts of faith came after, and were driven by, his faith in God.

Paul begins here to illustrate the difference between salvation by works and salvation by God's grace through faith in Christ. When we have a job, we get paid. That paycheck is not a gift. It is what our employer owes us in exchange for our work. Clearly, we can't demand that God "owes" us salvation on the basis of our works. First and foremost, as Paul has already demonstrated, none of us can earn being declared righteous by God. No matter how hard we try—which is not as hard as we could try (Romans 3:10)—we can't get the job done. God still owes us nothing.

In the following verse, Paul shows the difference of being declared righteous as a gift, as opposed to as a payment for services rendered to God.