Ye are our epistle written in our hearts, known and read of all men:

People's New Testament

3:2 Ye are our epistle. The church itself owed its existence to him. He could point to his work, to the disciples, as his letter of commendation. He was known by his fruits.

Written in our hearts. When he looked into his heart, he saw them enshrined there, and felt that he needed no commendation to them.

Wesley's Notes

3:2 Ye are our recommendatory letter - More convincing than bare words could be. Written on our hearts - Deeply engraven there, and plainly legible to all around us.

Jamieson-Fausset-Brown Bible Commentary

2. our epistle-of recommendation.

in our hearts-not letters borne merely in the hands. Your conversion through my instrumentality, and your faith which is "known of all men" by widespread report (1Co 1:4-7), and which is written by memory and affection on my inmost heart and is borne about wherever I go, is my letter of recommendation (1Co 9:2).

known and read-words akin in root, sound, and sense (so 2Co 1:13). "Ye are known to be my converts by general knowledge: then ye are known more particularly by your reflecting my doctrine in your Christian life." The handwriting is first "known," then the Epistle is "read" [Grotius] (2Co 4:2; 1Co 14:25). There is not so powerful a sermon in the world, as a consistent Christian life. The eye of the world takes in more than the ear. Christians' lives are the only religious books the world reads. Ignatius [Epistle to the Ephesians, 10] writes, "Give unbelievers the chance of believing through you. Consider yourselves employed by God; your lives the form of language in which He addresses them. Be mild when they are angry, humble when they are haughty; to their blasphemy oppose prayer without ceasing; to their inconsistency, a steadfast adherence to your faith."

Matthew Henry's Concise Commentary

3:1-11 Even the appearance of self-praise and courting human applause, is painful to the humble and spiritual mind. Nothing is more delightful to faithful ministers, or more to their praise, than the success of their ministry, as shown in the spirits and lives of those among whom they labour. The law of Christ was written in their hearts, and the love of Christ shed abroad there. Nor was it written in tables of stone, as the law of God given to Moses, but on the fleshy (not fleshly, as fleshliness denotes sensuality) tables of the heart, Eze 36:26. Their hearts were humbled and softened to receive this impression, by the new-creating power of the Holy Spirit. He ascribes all the glory to God. And remember, as our whole dependence is upon the Lord, so the whole glory belongs to him alone. The letter killeth: the letter of the law is the ministration of death; and if we rest only in the letter of the gospel, we shall not be the better for so doing: but the Holy Spirit gives life spiritual, and life eternal. The Old Testament dispensation was the ministration of death, but the New Testament of life. The law made known sin, and the wrath and curse of God; it showed us a God above us, and a God against us; but the gospel makes known grace, and Emmanuel, God with us. Therein the righteousness of God by faith is revealed; and this shows us that the just shall live by his faith; this makes known the grace and mercy of God through Jesus Christ, for obtaining the forgiveness of sins and eternal life. The gospel so much exceeds the law in glory, that it eclipses the glory of the legal dispensation. But even the New Testament will be a killing letter, if shown as a mere system or form, and without dependence on God the Holy Spirit, to give it a quickening power.

Matthew Henry's Whole Bible Commentary

Chapter 3

The apostle makes an apology for his seeming to commend himself, and is careful not to assume too much to himself, but to ascribe all praise unto God (v. 1-5). He then draws a comparison between the Old Testament and the New, and shows the excellency of the later above the former (v. 6-11), whence he infers what is the duty of gospel ministers, and the advantage of those who live under the gospel above those who lived under the law (v. 12 to the end).

Verses 1-5

In these verses,

I. The apostle makes an apology for seeming to commend himself. He thought it convenient to protest his sincerity to them, because there were some at Corinth who endeavoured to blast his reputation; yet he was not desirous of vain-glory. And he tells them, 1. That he neither needed nor desired any verbal commendation to them, nor letters testimonial from them, as some others did, meaning the false apostles or teachers, v. 1. His ministry among them had, without controversy, been truly great and honourable, how little soever his person was in reality, or how contemptible soever some would have him thought to be. 2. The Corinthians themselves were his real commendation, and a good testimonial for him, that God was with him of a truth, that he was sent of God: You are our epistle, v. 2. This was the testimonial he most delighted in, and what was most dear to him-they were written in his heart; and this he could appeal to upon occasion, for it was, or might be, known and read of all men. Note, There is nothing more delightful to faithful ministers, nor more to their commendation, than the success of their ministry, evidenced in the hearts and lives of those among whom they labour.

II. The apostle is careful not to assume too much to himself, but to ascribe all the praise to God. Therefore, 1. He says they were the epistle of Christ, v. 3. The apostle and others were but instruments, Christ was the author of all the good that was in them. The law of Christ was written in their hearts, and the love of Christ shed abroad in their hearts. This epistle was not written with ink, but with the Spirit of the living God; nor was it written in tables of stone, as the law of God given to Moses, but on the heart; and that heart not a stony one, but a heart of flesh, upon the fleshy (not fleshly, as fleshliness denotes sensuality) tables of the heart, that is, upon hearts that are softened and renewed by divine grace, according to that gracious promise, I will take away the stony heart, and I will give you a heart of flesh, Eze. 36:26. This was the good hope the apostle had concerning these Corinthians (v. 4) that their hearts were like the ark of the covenant, containing the tables of the law and the gospel, written with the finger, that is, by the Spirit, of the living God. 2. He utterly disclaims the taking of any praise to themselves, and ascribes all the glory to God: "We are not sufficient of ourselves, v. 5. We could never have made such good impressions on your hearts, nor upon our own. Such are our weakness and inability that we cannot of ourselves think a good thought, much less raise any good thoughts or affections in other men. All our sufficiency is of God; to him therefore are owing all the praise and glory of that good which is done, and from him we must receive grace and strength to do more." This is true concerning ministers and all Christians; the best are no more than what the grace of God makes them. Our hands are not sufficient for us, but our sufficiency is of God; and his grace is sufficient for us, to furnish us for every good word and work.