This section of Romans makes it clear that divisions in the church go back to the earliest churches.
The "strong" who are mentioned here apparently eat everything, observe all days as the same, and perhaps drink wine. The "weak in faith," mentioned in the first verse of this reading apparently abstain from meat, observe one day as more sacred than others--this was probably the Sabbath--and abstain from wine. More significant than these differences in lifestyle, however, were the attitudes that were dividing the church. Paul's commands toward both groups make it pretty clear that the "strong" were despising the "weak," while the "weak" were judging or condemning the "strong."
The behavioral differences in view here are adiaphora, "indifferent things," or "things that don't matter." These behaviors are not explicitly prohibited or commanded by scripture. They lie in a moral zone where each person must exercise conscience to decide how to proceed.
Differences in how we follow our consciences always have the potential to threaten our fellowship as believers in Christ. A story about Ruth Graham, wife of the famous evangelist, illustrates how differences can threaten our unity. Mrs. Graham, dressed and made up as would seem fitting for any American woman in the 1970s, attended a luncheon with wives of conservative pastors in Germany. These German Christians had more conservative ideas regarding how women should look. They did not believe that married Christian women should wear makeup or clothing that made them look too much like the world. As a result, a German pastor's wife, sitting across from Ruth Graham, became very upset. She thought it was shameful that the wife of this famous evangelist looked so worldly. Why, Ruth Graham was even wearing mascara! The German pastor's wife became so angry that she started crying right into her beer. Meanwhile Ruth Graham couldn't understand why the woman was crying, although it bothered her that a self-respecting pastor's wife was drinking beer at a meeting to prepare for an evangelistic crusade where Christians come together as the unified body of Christ.
In this text and what follows, Paul shows no sign he recommends that people who are more liberated in conscience teach those with more sensitive consciences to change their positions. In fact, he sounds postmodern in 14:14 when he says that for the person who thinks a certain food is unclean, it is unclean. This leads him to say in the next verse, "I am not walking in love if what I do or eat causes a fellow believer to be grieved." Notice he makes no allowances for what I intend or don't intend to do. If I have a more robust conscience and a believer around me is grieved, then I have not been acting in love by first asking how my behavior will affect others around me.
One summer I went on a short missions trip to rural Guatemala. I knew that men weren't supposed to wear short pants, so on the first day at our ministry site--a Sunday--I was out in long pants, playing soccer with some village boys. My team leader came out and said, "Mark, there are some pastors here who are asking why you, a participant in this conference, are playing a competitive game like soccer on a Sunday." It turned out that the believers to whom we were ministering thought there was something wrong with competitive sports. They would not think of playing soccer on a Sunday! It was like Paul said here in 14:5--one person places one day above the others while another person views all days alike. On that Sunday in Guatemala, I had to respect the sensibilities of the pastors who were there and walk off the field.
Paul says that if both sides are doing their action "for the Lord," then both positions are valid and must be respected (14:6). Is Paul saying that I have to curtail my freedoms because of others' sensitivities? For relationships within the church, this is exactly what Paul is saying and confirmed by his words on verses 7-9, that we, like Christ, are not living for ourselves. We are here to live for the Lord.
Another reason Paul gives for respecting the behavior of others' in indifferent matters is that each believer will stand before God in judgment. It is not for us to judge other people. If they can perform their activities in good conscience for the Lord, then we can let them continue.
Indeed, the theme that God will finally judge is not just an idea that keeps us from taking revenge, as we see in Romans 12:19. God's judgment is also a powerful idea that keeps me from judging or despising those who live out their Christian convictions in ways different from how I live (14:4, 10-12). Jesus said, "Do not judge, so that you may not be judged" (Matthew 7:1). Paul is applying Jesus' words to differences within the church. His goal for our church is presented in his benediction in Romans 15:5-6, that instead of using our words to despise or judge others in our fellowship, we glorify the God and Father of our Lord Jesus Christ "with one voice!"