Whether Jew or Gentile, Romans 3:21-4:25 is a very challenging piece of Scripture to wrap your mind around. Modern society has tried to make God out to be some evil sorcerer in the sky who wants to make our lives miserable unless we attempt to appease him with sacrifice. However, if you’re a Christian, Paul tells us he has already been appeased because of the atoning and sacrificial atoning death of Jesus Christ (3:25).
Paul starts off his explanation of it all with verse twenty-one “But now the righteousness of God has been manifested apart from the law, although the Law and the Prophets bear witness to it” The righteousness of God is Jesus Christ himself, and He is the only true righteousness of God. You can do nothing to earn this righteousness, and the Law and the Prophets have been pointing to this time for years. The very next thing Paul tells us is that the righteousness of God is attainable by faith for all who believe in Jesus Christ (my paraphrase). He spends the rest of chapter three explaining how we are justified by faith alone and then in chapter four gives us the example of Abraham’s faith.
In continuing to expound upon our own unrighteousness, Paul adds verse 23 “for all have sinned and fall short of the glory of God, ” proving that we are not worthy to be in the presence of God. Leon Morris says, “This clear statement of universal sinfulness is basic to Paul’s understanding of the human predicament and also of the salvation Christ brought. Were it not for our sin there would have been no need for Christ’s redemptive activity; because of our sin there is no possibility of achieving salvation by our own efforts.” Paul goes on to strengthen his argument in verses twenty-eight thru thirty. He is telling his readers yet again that only faith apart from the Law will justify them, no matter if they are Jew or Gentile, since God is one he justifies all by their faith. “For if, as Jews proudly confess, there is only one God, then this God must be equally God of Gentiles as well as Jews. Rightly understood, this demolishes any ultimate difference between Jew and Gentile before the Lord.”
Paul begins to conclude his argument by using Abraham as the greatest example of justification by faith. Chapter four lays out how Abraham trusted the Lord and in doing so showed his faithfulness and it was credited to him as righteousness. But in doing so, many people will say that there is a contradiction in the Bible, because Paul says that justification is from faith alone while James say that faith without works is dead. How can this be? R.C. Sproul explains that when James is referencing Abraham he is quoting from Genesis 22 and Paul is referring to Genesis 15. They are both arguing for justification, and they are each referring to different aspects. Wayne Grudem explains, “Here we must realize that James is using the word justified in a different sense from the way Paul uses it. In the beginning of this chapter we noted that the word justify has a range of meanings, and that one significant sense was “declare to be righteous,” but we should also notice that the Greek word δικαιόω (G1467) can also mean “demonstrate or show to be righteous.”
Understanding these things should allow us to live out our faith with a greater enjoyment knowing that there is nothing we can do to merit our justification.
 The Holy Bible : English Standard Version. (Wheaton: Standard Bible Society, 2001), Ro 3:21.
 The Holy Bible : English Standard Version. (Wheaton: Standard Bible Society, 2001), Ro 3:23.
 Morris, Leon. The Epistle to the Romans. (Grand Rapids: Edermans, 1988), 177.
 Moo, Douglas J. The NIV Application Commentary- Romans. (Grand Rapids, MI: Zondervan, 2000), 139.
 Sproul, R.C. St. Andrew's Expositional Commentary-Romans. (Wheaton: Crossway, 2009),111.
 Wayne A. Grudem, Systematic Theology : An Introduction to Biblical Doctrine (Leicester, England; Grand Rapids, Mich.: Inter-Varsity Press; Zondervan Pub. House, 1994), 731.