Roman 14 and 15 speak about accepting one another in Christ's Body. As believers, we don't all think alike in every matter. One day when Christ returns and our minds become perfect, we will agree 100% on every doctrine and we will recognise what true spirituality is and what soulishness and worldliness are. But now we all have different opinions on these matters, because even if we are sincere and wholehearted, our minds have still been warped by the effects of sin. No-one has a perfectly clear understanding of anything. We see everything darkly through a glass (1 Corinthians 13:12). So, when we see something different in others, we should not be stubborn imagining that we are right and others are all wrong. That is how divisions come in the Body of Christ. There are clear and important truths in Scripture - especially concerning the Person and work of Christ. Jesus Christ is fully God and fully man and He died for the sins of the world and rose again and is the only way to God the Father. On such doctrines, we do not yield one bit. But there are other doctrines that are not fundamental.
Water-baptism, though not essential for salvation is still an important doctrine for local churches. It will be impossible for one who believes in baptising children to work together in the same church with another who believes that child-baptism is un-Scriptural - for they will be clashing constantly. But even though we may not be able to work together with such brothers, we must still accept him as a brother in Christ, if he is born again - for God has accepted him. We can fellowship together even if we can't work together. The tragedy today is that many believers feel that if they cannot work with a person, they cannot fellowship with him either. That is where Chapters 14 and 15 come in.
Do you see a brother who is weak in the faith? Accept him. How should you accept him? "Just as Christ accepted you" (Rom 15:7). Did Christ accept you when you were perfect? No. Then why do you expect your brother to be perfect before you accept him? How weak and foolish we all were on the day we were born again. We knew nothing about God and we were all defeated by sin. Yet the Lord accepted us. He saw many things wrong in us, yet He accepted us. If we do not accept others whom God has accepted, we are proud and imagine ourselves to be more spiritual than God Himself! This is how cults are built - not only by wrong doctrines, but also by wrong attitudes towards other children of God. We should not make our petty rules and laws the basis for accepting other members of Christ's Body.
"Why do you judge your brother?" (Rom 14:10a). That's an outward action. "Why do you regard your brother with contempt?" (Rom 14:10b). That's an inward attitude. We must avoid both. When our hearts are enlarged to accept all whom God has accepted, just as they are, then we come to the culmination of the message of the gospel. "In one accord (with others in Christ's Body) and with one voice, we glorify God" (Rom 15:6).
The last chapter, Romans 16 includes greetings from Paul to different believers in Rome. In the church in Rome, there were five house churches (verses 5-15). They didn't all meet together in one hall as a mega-church. The church in Rome was very large, but they met in different houses in small groups. Even though Paul had never been to Rome, he took an interest in knowing different people in the church there and greeted them.
Finally: The expression 'the obedience of faith' (Rom 16: 26) occurs here at the end of this letter just as it does at its beginning. God had given Paul the calling to lead people not only to faith but also to obey what they believed. Faith without works of obedience is a dead faith - like a lifeless body. Under the old covenant, the emphasis was on obedience. Under the new covenant, it is on the obedience of faith. We obey God now, knowing that every command comes from a loving Father and is designed for our very best.