Footnote of the NET Bible on 1 Cor 3.4, "For whenever someone says, 'I am with Paul,' or 'I am with Apollos,' are you not merely human?" —
6 tn Grk “are you not men,” i.e., (fallen) humanity without the Spirit’s influence. Here Paul does not say “walking in accordance with” as in the previous verse; he actually states the Corinthians are this. However, this is almost certainly rhetorical hyperbole.
Paul's comment seems straightfoward. Whenever someone says such things, such a person is not spiritual. He is carnal. He reverts to his fallen humanity without the Spirit's influence. Now perhaps the writer of the NET Bible comment says, "I am a Baptist," or "I am an Assembly of God member," or "I am a Catholic," and himself falls within this category. Of course, he'd want to consider Paul's statement as "almost certainly rhetorical hyperbole." When you participate in a division far worse than than in Corinth, you'd rather not think of yourself in such terms.
Jeremiah Tatum wrote in his article, "The biggest mistake Churches of Christ have made in the last 50 years":
I’m going to be bold now and put the majority of the blame on the common disciple. For the most part I don’t believe that preachers and missionaries who are in the trenches have contributed to the problem. In fact we have often had to run interference. Mostly it is the members of the Lord’s church, who have either not been listening or who have not taught themselves, who use language like “I’m a church of Christ.” Or who use phrases like, “You have to be a church of Christ.” Or even, “Well the church of Christ teaches…” Such Christians who misrepresent the kingdom are doing the church and the world’s population a disservice by turning the body of Jesus into a denomination that follows a creed.
This is not a laity versus clergy problem. This is a generalized problem, a denominational concept of the church. It is leaders who hang "CHURCH OF CHRIST" on their buildings. Leaders have denominationalized the church as much or more than their followers. When leaders take down the names (for that's what it is) from their buildings, maybe, just maybe, the laity will listen to the preachers' rants about their use of language.
I use laity and clergy referring to the brethren, because we got it in most places. Stan Mitchell observed, in his last article on Forthright published today but written before his death last week: "We say we do not believe in the clergy-laity system, but we certainly act like that’s what we want." It's there for those willing to see.
The more a congregation of the Lord imitates the divisive denominations, the more their leaders will make sense and seem to be a resource for its work.