If we say that all the human race are our brothers, we would lose the difference between ''the many called'', the ''few chosen'' and ''the ones who are not even called (unbelievers)''. I can also understand when somebody says that 'EVERY ONE is our brother'-metaforically; it make sense because God is the creator and we all are part of His creation and because eventually we will be ALL brothers and sisters. However, for the moment, I don't believe that Paul would call some random pagan person a brother.
I am persuaded to believe that most Christian with whatever degree of carnality are my brothers and sisters, even so if they preach Jesus by PRENTENCE (as Dennis quoted it).
''From what we have read, we can clearly see that the Corinthian Church was a congregation of "carnal BELIEVERS." Of course, you can be a believer and yet be carnal. Listen, the entire two billion member Christian congregation around the world ARE BELIEVERS. That is they believe that Jesus is the promised Messiah and Christ, and that there is salvation in Him. That is what makes them believers. From there they fall into all kinds of categories and doctrinal differences, but nonetheless, they are believers regardless of how many of them are "yet carnal."
I believe that the key phrase in all this is to not become "unequally" yoked. Now Paul said with unbelievers, which makes it obviously the wrong thing to do. First you would be "yoked unequally" and to make it worse, to an "unbeliever." Now Paul tells us that this admonition came from him personally under God's inspiration certainly, nonetheless he adds: But to the rest speak I, not the Lord" (I Cor. 7:12).
And so I will take a little liberty myself and suggest that when it comes to marriage (remember Paul is not specifically speaking of marriage here), and say that we should neither become unequally yoked together with BELIEVERS. In other words, we should not become unequally yoked with another, but especially Unbelievers.
The word translated "unbelievers" is apistos and it means "without [Christian] faith, a heathen, incredible, faithless, infidel, unbeliever." It is the same word translated "infidel" in verse 15, although infidel usually signifies something a little stronger than just lacking faith.
We do not need to totally avoid unbelievers, but we are not to become unequally "yoked" to them either. Paul permitted a certain amount of socializing with unbelievers:
1Co 10:27 If any of them that believe not bid you to a feast, and ye be disposed to go; whatsoever is set before you, eat, asking no question for conscience sake.
Probably most of us have some relative in our family that is not a believer, but with whom we could have certain social intercourse with.
For sure Paul is not forbidding interaction with "The many called and the few chosen." However, even there, we should not become unequally YOKED with them, or how can we say we came out of her as God's people (Rev. 18:4).''
Excerpt ''UNEQUALLY YOKED'' by L.Ray Smith