Unlike other peddlers of the Gospel, Paul does not need “letters of recommendation” to introduce himself to the church (2 Cor 3:1-3). This is a metaphor drawn from the common Roman practice of having a letter of introduction when visiting someone, especially if you intended to instruct and correct the new group. A letter of recommendation or introduction was common in the ancient world. A letter (συστατικός) would confirm a person’s identity and qualifications.
If a Christian teacher arrived in a church, it would not be considered rude at all to ask to see a letter of recommendation in order to confirm they are a legitimate teacher and qualified to teach. In the modern world, we might ask a pastor where they were educated and through what organization they were ordained. This confirms they are trained and authorized in a particular denomination. Paul wonders (sarcastically) if he needs to get a new letter of recommendation to the congregation, as if he were coming to the church as a complete outsider for the first time. This is to say, “Are we starting all over again”?
Instead of physical letters of recommendation, Paul says the church at Corinth itself his recommendation. He calls on the church to remember the fact he was the one who brought the gospel in Corinth in the first place and established the church. He spent eighteen months training the leaders of the church before moving on to Ephesus. He does not need a letter of recommendation, since the people in the church itself are his letter! The whole world can read Paul’s letter by looking at the Corinthian church.
“Written with ink” would refer to a letter written on papyri, but written on stone would recall the Law of Moses to a Jewish reader. If a Gentile was unfamiliar with the story of Moses receiving the Commandments in Exodus 31:18, then they might have thought of a physical inscription on a monument. These were so common they could not walk through Corinth without seeing an inscribed monument, placed in a public place for all to see.
Rather than written in a physical form, God has written this letter of recommendation in the hearts of the Corinthians by the Spirit of God. “Engraved on hearts of flesh not stone” is an allusion to Ezekiel 11:19, 36:26. In Ezekiel, the new covenant would be written on the heart, not stone as the old covenant was.
Paul has moved from a letter of recommendation to the idea of the covenant. He does not need a physical letter to be qualified to minister to the church because he has been appointed a minister of the New Covenant, which the Corinthian believers themselves participate in by having the Holy Spirit.
Rather than having authority coming from a letter of recommendation or a document like the Torah, Paul’s authority come from God through the Holy Spirit. God himself has recommended Paul through the ministry of the Holy Spirit, and he has enabled him to be a ministry of this new covenant through the power of the Holy Spirit.
If we think about the metaphor of a letter of recommendation, the content of the letter is usually your qualifications and accomplishments. Paul has already said he does not have any personal qualifications to be the Apostle to the Gentiles, yet God called him anyway; now he denies any accomplishments since God has done everything, and apart from God Paul has done nothing!
If Paul were writing a letter of recommendation for himself, it would be something like: “I am not qualified for this job, but God thinks I am and he will accomplish the tasks assigned.” This is the opposite of the way the Roman world would think about leadership. For the Romans, one was worthy of respect because they had accumulated honors and held the right offices. For Paul, he is a minister, a servant, of the New Covenant rather than the Apostle to the Gentiles appointed personally by God, with 30 years experience as a church planter, and all the other resume-padding typical of the world.
Humble leadership like this is something often talked about in the contemporary church, but it is not as often practiced. It is easy for the leader to think too highly of themselves, to think of themselves as the boss, or worse, a CEO of a major corporation who expects an impressive compensation package all the perks that come with an executive position. By shifting his perspective from the way the Roman world thought to the way God thinks, Paul revolutionizes pastoral leadership.