What does 1 Corinthians 3:6 mean?

Paul has described the Corinthian Christians as infants, still living in the flesh despite being given access to the power of the Holy Spirit. Now he is explaining to them, as if to children, why it is so foolish to divide themselves into factions based on which Christian leader they are loyal to.

In the previous verse, Paul wrote that he and Apollos are both merely servants of the Lord. God used each of them to bring the Corinthians to faith in Christ, but they should not be the focus of that faith.

Now Paul adds something that is helpful in this context but is also valuable in our understanding of how God's work is accomplished on earth. Paul uses an agricultural metaphor. Paul planted the gospel; he introduced the people in Corinth to the message of the forgiveness of sin through faith in Christ. This parallels Jesus' description of gospel evangelism as sowing of seeds (Matthew 13:1–9, 18–23). Paul describes Apollos as watering this seed. Likely, he means Apollos provided additional teaching, helping the seed of the gospel to take root in the hearts of the Corinthians. It might also mean Apollos was there to begin guiding the believers of Corinth in their discipleship.

Both men served God by doing the tasks given to them. God, though, is the one who caused the seed to grow. As Paul described in the previous chapter, God gave to the Corinthians the ability to believe the gospel through the Holy Spirit. In the end, God's work among the Corinthians is the work that mattered most.