Romans 3:21, “But now the righteousness of God without (apart from) the law is manifested, being witnessed by the law and the prophets;”
The Gospel was pictured or foreshadowed in the Law. The Law convicted Jews and Gentiles of sin. It pointed to a need for a Savior.
Romans 3:22-23 “…The righteousness of God … is by the faith of Jesus Christ.” For those who believe, “there is no difference [between Jew and Gentile]. “For all have sinned, and come short of the glory of God;” This epistle emphasizes repeatedly that true justification comes by faith in Jesus. What Paul wrote was not a new theology because salvation through Christ was foreshadowed in the Law and prophesied through the prophets. The prophet Habakkuk wrote, “The just shall live by faith” – not by works.
Romans 3:24, “Being justified freely by his grace through the redemption that is in Christ Jesus:”
It is by God’s grace that the gift of justification is received through Christ. Justification is not earned. Paul was bringing a message of hope. We all stand condemned in our own righteousness. Isaiah wrote, “We have all become like one who is unclean, and all our righteous deeds are like a polluted garment. We all fade like a leaf, and our iniquities, like the wind, take us away. which is as filthy rags.” (Isaiah 64:6 RSV). Paul then proceeded to tell about the “redemption that is in Christ Jesus.”
Romans 3:25, “Whom God hath set forth to be a propitiation (“a mercy seat” in Greek) through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;”
Paul was explaining that Jesus’s death had a purpose – it was to be a propitiation to satisfy the demands of justice for Adamic sin. Under the Law, typical atonement occurred when blood was sprinkled on the Mercy Seat (the place of propitiation). Paul was saying that Jesus is the means of true atonement—that faith in his blood brings justification and forgiveness.
Romans 3:26, “To declare, I say, at this time his righteousness: that he (God) might be just, and the justifier of him which believeth in Jesus.”
God is just, and He is also the Justifier. God did not ignore justice; He provided justification to sinners by faith in Jesus’s blood.
Romans 3:27- 29, “Where is boasting then? It is excluded. By what law? of works? Nay: but by the law of faith. 28 “Therefore we conclude that a man is justified by faith without the deeds of the law. 29 Is he the God of the Jews only? is he not also of the Gentiles? Yes, of the Gentiles also:””
Here Paul summarized the argument. It is one God, which shall justify the circumcision by faith, and uncircumcision through faith.
Romans 3:31, “Do we then make void the law through faith? God forbid: yea, we establish the law.”
The Law in the Old Testament does not conflict with the Gospel.The ceremonial features of the Law ended when the antitype had come, The sacrifices represented Jesus and the Church. Jesus said, “Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfill” (Matthew 5:17). Jesus came to magnify or fulfill the Law. Jesus did not “make void” the Law.