I do not know if you have ever been involved in a church fight over an issue like drinking, smoking, movies, dances or whatever, but if you have, you know that tempers can get very hot. People get upset, and factions form; divisions and feuds break out. Although, I have never heard of any church fight on those grounds that was any worse than the attitudes that Jews and Gentiles had toward one another in Paul’s day.
The Jews held the Gentiles in contempt; they called them dogs. They would have nothing to do with them. The Jews even regarded it as sinful to go into a Gentile’s house and they would never dream of eating with a Gentile. They were held with utter contempt. Do you remember the time in the book of Acts, when Peter got into trouble with his Jewish friends because he went into the home of Cornelius the centurion, and ate with him. He had to defend himself by saying that the Holy Spirit sent him there, and used him there. In fact, not only did the Holy Spirit send him there, the Gentiles even received the Holy Spirit and spoke in tongues after he told them about Jesus. Wow! Of course, the Gentiles felt the same way about the Jews. They hated them. They called them all kinds of names; they looked down on them. We still see that hated today, but it was just as bad back then.
Both sides hated one another, and tried to have nothing to do with one another. Yet, Paul says that through the work of Jesus, God is able to heal that kind of division. I have witnessed the Spirit of God healing racial hatred. I have seen blacks and whites worshipping the Savior arm-in-arm! So how did Jesus do it? According to Paul, Jesus began his work by becoming himself a minister of circumcision. The version I have says he “became a servant of the Jews.” Another version says that “Christ became a minister of the circumcision,” which is another name for the Jews. Actually what the text says is, “he became a minister of circumcision,” which does not necessarily refer to the Jews as a people, but refers to their customs and rituals and ceremonies.
You have quotations from the Psalms (the Writings); from Deuteronomy (the Law); and from Isaiah (the Prophets). So you have the Law, the Prophets, and the Writings all agreeing that God can work out these kinds of problems. From the past, from the present, and from the future there is encouragement to work them out. What Paul is really saying is, “You do not need to separate; you do not need to split; you do not need to fight; you do not need to sue one another; you do not need to quit. You can work the problems out, for there is help available from all these sources, and God is honored and glorified when you do so.”
If interested, you can download the entire study of The Letter to Christians at Rome