What does 1 Corinthians 3:10 mean?
The previous verse completed a metaphor about planting a field. Paul pictured himself and Apollos as simple laborers among the field of the Corinthians, echoing something of Jesus' parable of the sower (Matthew 13:1–9, 18–23). The field belongs to God and that's where the Corinthians should focus their allegiance, not on any human leader.Now Paul has shifted to the metaphor of constructing a building, with a closely related point in mind. He pictures himself as a skilled or wise master builder by God's grace. In that role, he is the one who laid the foundation. The building is the church, the community of Christians, in Corinth. The following verse will show that the foundation Paul put in place was Jesus Christ.
In other words, Paul is the one who introduced Christ and the gospel to the Corinthians. He began the work, providing the stable, supporting "starting point" for everything meant to come after. Now others have come to build on the foundation as the church grows both in numbers and, hopefully, in spiritual maturity.
Paul warns that those who continue the work be careful how they build in their teaching and leadership. He doesn't seem to be calling out a problem with the current teachers and leaders. He is cautioning these leaders about the building work yet to be done. One cannot haphazardly throw materials into a stack—some building work is better than others.