What does 1 Corinthians 3:4 mean?

Paul now directly addresses the source of quarreling and division among the Christians in Corinth, first introduced in chapter 1. There he wrote that the church in Corinth had divided itself into groups based on whether a person claimed loyalty to Paul, Apollos, Peter, or Christ (1 Corinthians 1:12). There may have been even more groups, but Paul's point was that the church was being split according to those loyalties.

Some of this division may have been about personality. Paul has described himself as weak, fearful, and trembling when he was with the Corinthians, not presenting the gospel in an impressive way (1 Corinthians 2:1–5). We know from Acts 18:24–19:1 that Apollos was an "eloquent" man, who taught the Scriptures fervently, boldly, and powerfully. He came to Corinth after being trained in Ephesus by Paul's co-workers Priscilla and Aquila.

Perhaps some of the division was about ethnicity. Both Paul and Apollos were Jewish, but it's possible some of the Jewish Christians were more comfortable with Peter's or Apollos's approach to the issues of Jewish tradition and heritage than with the others. It's not clear that Peter ever visited Corinth, however.

For Paul, the subtle nuances behind these divisions don't matter. The problem is that they exist at all. These squabbles are evidence that the Corinthian Christians are behaving like unbelievers, or immature Christians, demanding their own way, rather than as Holy Spirit-empowered believers learning to express God's sacrificial love to each other.