“Ye are our epistle written in our hearts, known and read of all men” (II Cor. 3:2).
Since the Corinthians were saved by Paul’s gospel (I Cor. 15:1-4), the apostle calls them his epistles. Webster said that an epistle is “a writing… communicating intelligence to a distant person.” Surely the “intelligence,” i.e., the information that the Corinthians communicated to the world was that even the most sinful of men could be justified by God’s grace (I Cor. 6:9-11).
But if Paul could say to the Corinthians, “ye are our epistle,” why does he go on to say that they were “manifestly declared to be the epistle of Christ” (II Cor. 3:3)? Ah, a letter written by an apostle under the inspiration of the Spirit was a letter from Christ! And since everyone who is saved today is also saved as a result of having believed Paul’s gospel, you too are a Pauline epistle! And so the debate over whether Paul wrote 14 or just 13 epistles is over! The apostle penned millions of letters over the past many centuries.
It has often been said that you are the only Bible that some people will ever read, and this is sadly so. What a responsibility this places on us to live lives worthy of the Lord! Handwriting experts can tell who a letter is from by the way the i’s are dotted and the t’s are crossed, etc. Can men tell who sent you, Christian friend? Are you dotting all the i’s and crossing all the t’s when it comes to godliness? Many Christians who wouldn’t dream of corrupting the written word of God found in Paul’s epistles (II Cor. 2:17) carelessly corrupt the living epistles of their lives by inconsistent godliness. Remember, letters don’t get time off! They read the same today as they did yesterday, and we too should be as consistent in our Christian testimony. If you are holy on Sunday and a holy terror the rest of the week, this is unacceptable to God (Rom. 12:1,2).
Since the epistle of our life is “known and read of all men” (II Cor. 3:2), we want to make sure we don’t give men a faulty “reading” of Christ. All men understand by the stars that God exists, as the stars too are known and read of all men (Psa. 19:1-3). But while all men understand by the stars that God exists, all men understand by us what kind of God He is. When we live “soberly, righteously, and godly” (Titus 2:12), we prove to others what is acceptable to the Lord (Eph. 5:8-10). source