Paul says he could not speak to them as spiritual people but as people of the flesh, as infants in Christ, to whom he gave milk and not solid food because they were not ready. As long as there is jealousy and strife among them, they are still behaving in a merely human way. When one says he follows Paul and another Apollos, they show they think like anyone in the world.
Paul asks what Apollos and he are: servants through whom they believed, each as the Lord gave. Paul planted, Apollos watered, but God gave the growth. The one who plants and the one who waters are one, and each will receive a reward according to his labor. They are God's fellow workers, and the Corinthians are God's field and God's building.
As a skilled master builder, Paul laid the foundation, which is Jesus Christ, and someone else builds on it. Each must take care how he builds, for each one's work will be tested by fire on the day of judgment: work of gold, silver and precious stones will last, and work of wood, hay and straw will burn. The builder whose work survives will receive a reward, and the one whose work is burned will suffer loss, though he himself will be saved, as through fire.
Paul adds that they are God's temple and God's Spirit dwells in them. God will destroy anyone who destroys his temple. He urges that no one deceive himself: whoever thinks he is wise by this age's standards should become a fool in order to become wise, for the world's wisdom is folly with God. No one should boast in men, since everything belongs to them: Paul, Apollos, Cephas, the world, life, death, the present and the future. They are Christ's, and Christ is God's.