I completely agree that Paul wasn't writing about opinions on doctrinal issues.

I also believe that he wasn’t talking about Baptists getting along with Lutherans. I believe that his point was directed much more at interpersonal relationships. To many of the Jews and Gentiles viewed themselves as being the “chosen.” Paul points out that ‘we’ don’t choose who God accepts, He chooses Eph. 1:5 , “Having predestinated us unto the adoption of children by Jesus Christ to himself, according to the good pleasure of his will.”

Paul teaches that the righteous were “quickened together with Christ.” Once again He chooses not us. Chapter 2 of Ephesians also makes it clear that the Gentiles are accepted into the Body, although they were formerly aliens (a term that the Jews probably used to define the Gentiles). Christ broke down the dividing wall between the Jews and Gentiles. Those two groups are not “fellowcitizens.”

Paul’s point in the first three Chapters of Ephesians is that God’s plan was to send Jesus to save man, both Jew and Gentile and that these two groups must understand this revealed mystery. While this issue deals with the overall body of Christ (or maybe better put the family that is named after Him), the application of the teaching is revealed in the balance of the book. The application is that understanding God’s desire for the Jews and Gentiles was important because in their interaction with each other the two groups needed to be unified in purpose and also needed to show love for each other. While the point was applicable to the entire Body, its application was intended at a local level…as a person with Jewish heritage you needed to understand this basic principal so that you would treat the Gentiles Christians that you came into contact with in the right way and vice versa. In Chapter 4, Paul points out that members of the Body are given gifts by God that are intended to be used “for the perfecting of the saints…for the edifying of the Body.” The gifted teacher in Ephesus has the primary responsibility of edifying the Christians that worshiped with him.

I do question a portion of your point; however. You state “…opinions such as cups, classes, preachers, colleges, etc..” My question is in the detail of the point. You or I don’t decide who is righteous in God’s eyes. Condemning others is a dangerous slope to go down and there are many scriptures to back that up. However, how we define “opinion” is a massive issue. How we define “opinion” has torn church families apart. It has worked in both directions. Legalistic views have torn groups apart (e.g. if you use more than one cup your going to hell). But permissive attitudes supporting acceptance at all costs have also torn groups apart (e.g. why not have female ministers). Who’s right? The answer is neither and that is a current day application of Ephesians. The Corinthians seemed to have been the later example. They boasted of the righteousness even though they had a sinful fornicator among them. Were the Christians at Ephesus suppose to overlook the action by calling it opinion? No it wasn’t opinion, it was error that needed to be remedied.

Too many Jews in the first century church are like today’s legalistic Christians. They wanted to force circumcision and other requirements that weren’t a part of God’s expectations of the Body under the new Covenant.

So how do we define “opinion?” Some of the items you brought up may not be opinion. Is a preacher opinion? Maybe and maybe not. What about a preacher that is not under elders, is it his church? What about a female preacher? What about a homosexual preacher? Is the preacher the only one that teaches or edifies? What about a choir? or a 12 piece band? Is that still opinion? You see, I could go on and on. And I guarantee that I can find a baptized believer that will tell you that everyone of those topic and more are opinion.

This topic comes down to where you want to draw the line. I hate the idea of a line at all but I’m also not very comfortable erasing a line just to draw another one.