In chapter 3 Paul starts by talking about letters of recommendation. Apparently, it was a problem in the church, perhaps because of Paul’s enemies who came to the Corinthian Christians with some kind of recommendation letters from others. They belittled Paul’s ministry because he did not have such letters. That is true, of course, Paul did not have any. Then again, Paul was an apostle, and who would be able to write letters for him? Paul conducted his ministry by the authority of the Lord Jesus Christ, and as he was writing his first and second epistles to the Corinthians he did so by the inspiration of the Holy Spirit.
Nevertheless, Paul says that there are letters of recommendation that he has, but they are not those that everyone thinks of. They have not been written by another person, or some ecclesiastical body in order to give authority to Paul. Instead, the Corinthian believers are Paul’s letters of recommendation. He tells them that they can see the effects of the Gospel Paul preaches in their own hearts. So when people ask what great things are happening today, and where they are being found, Paul gives us the answer. Sinners are finding forgiveness and newness of life.
Have you ever thought of it that way? That is the only really great and new thing that is happening in human history. What you read in the newspapers is always the same thing. My father used to say, “It’s just the same things happening to different people.” Have you ever thought of it that way? If you pick up the newspaper or watch the news, you hear about the same problems, sins, tragedies, and disappointments. But God’s kingdom of grace is advancing as the Gospel is preached and newness of life comes from God’s Spirit into the hearts and minds of people who surrender to Jesus Christ. Notice, too, that when Paul speaks of his ministry it is not in terms of how important he considers himself to be, but in terms of what God does through him.
In the third and last section Paul discusses the personal transformation of those who have heard and respond to that Gospel. The way he does this is interesting. Paul mentions in verse 6 that God has made us—that is, the apostles—competent as ministers of a new covenant. Jeremiah speaks about a new covenant, which is probably where Paul picks up on the idea. There was an old covenant, the covenant of the law, which was characterized by the need to do it in order to live. But since it was impossible to perform it all perfectly, it led to death. Out of that background, God declares through Jeremiah,
“The time is coming,” declares the LORD, “when I will make a new covenant with the house of Israel and with the house of Judah. It will not be like the covenant I made with their forefathers when I took them by the hand to lead them out of Egypt, because they broke my covenant, though I was a husband to them,” declares the LORD. “This is the covenant I will make with the house of Israel after that time,” declares the LORD. “I will put my law in their minds and write it on their hearts. I will be their God, and they will be my people” (Jer. 31:31-33).
God was going to provide for the keeping of the law by an internal change in the lives of those who should hear the Gospel of Jesus Christ. When Paul talks about a new covenant, that is what he is thinking of. Also, it seems to me as if this set off a whole train of thought concerning the new covenant. From there he begins to expound upon the differences between the two covenants.
The first contrast is between the letter and the Spirit, in verse 6. The old covenant, which is the Law of Moses, is written down and can be read, but by itself it does not change the heart. On the other hand, the new covenant is of the Holy Spirit, who produces changes in people.
Related to this is the second contrast, also in verse 6, which is that the letter kills while the Spirit gives life. The old covenant pronounces a judgment. We cannot keep it, and so the law condemns us. However, the Spirit gives life. He quickens our spiritual lives which were once dead in sin.
