Paul shifts analogies from agriculture to architecture (1 Corinthians 3:9c-17). In the previous section Paul referred to the church as God’s field and those who minister in it as God’s fellow workers (3:5-9b). Paul saw himself as a planter and Apollos as a waterer.
In this section, Paul considered himself a wise master builder who laid the foundation of the building. “Another builds on it” (Apollos?). His statement, “But let each one take heed how he builds on it” seems to indicate more that Apollos (cf. 4:15). Those who taught at Corinth and those who teach today in every place must take heed how they build. The materials they use (what they teach) must be consistent and in line with the foundation – Jesus Christ.