In this passage, Paul gives a basic definition of a minister. He begins by explaining what he did among the Corinthians: he was like a builder, who laid a foundation. However, at the present time, someone is building upon his foundation. Furthermore, Paul warns that that person must be careful how he builds upon it. The reason for this is that the foundation is already there, which is Jesus Christ. Therefore, the only materials that can be used to build upon it are metals, stones, wood, hay, and straw. However, Paul says, the work that is done upon the foundation will be tested on the day of judgment, and the method of testing will be like fire, which will burn anything that is not of eternal value, but leave whatever is of eternal value. Therefore, those who have built with eternally valuable things will be rewarded, but those who have built with things of only temporal value will not be rewarded for them.
In verse 16, Paul continues the illustration of the Corinthians as a building, and says that they are a temple of God, and that His Spirit dwells within them. Therefore, if anyone destroys them, that person will be destroyed because they are holy.
In verse 18, Paul warns the Corinthians against deceiving themselves. Then, he tells those who think they are wise in the eyes of the world that they must become foolish so they may truly become wise. The reason for this is that worldly wisdom is foolishness to God. Therefore, He catches those who are wise in the world’s estimation, and He finds their reasonings to be useless. Paul concludes that, for those reasons, no one should boast about men. Another reason is that the Corinthians have everything, including their spiritual leaders because they belong to Christ, and He belongs to God.
In verse 1 of chapter 4, Paul gives the correct attitude toward ministers: that they are servants of Christ, and stewards of God’s word. Furthermore, they are faithful men because they are stewards. However, Paul says, he finds the experience of being judged by the Corinthians to be of no importance, and he does not judge himself. The reason for this is that he knows of no habitual sin in his life, but he recognizes that that does not mean that there is no such sin in his life. Rather, God is the one who correctly judges himself. Therefore, Paul concludes, the Corinthians ought not to judge everything about anyone before the day of judgment, which will be at the second coming of Christ, who will reveal every secret of men. At that time, God will praise those who deserve it.