The conversion and new life of the Corinthians were Paul's certificate as an apostle. They were a certificate known, he says, and read by all men. Often there is a certain awkwardness in the presenting of credentials. It embarrasses a man when he has to put his hand into his breast pocket, and take out his character, and submit it for inspection. Paul was saved this embarrassment. There was a fine unsought publicity about his testimonials. Everybody knew what the Corinthians had been, everybody knew what they were; and the man to whom the change was due needed no other recommendation to a Christian society. Whoever looked at them saw plainly that they were an epistle of Christ; the mind of Christ could be read upon them, and it had been written by the intervention of Paul's hand. This is an interesting though a well-worn conception of the Christian character. Every life has a meaning, we say; every face is a record; but the text goes further. The life of the Christian is an epistle; it has not only a meaning, but an address; it is a message from Christ to the world. Is Christ's message to men legible on our lives? When those who are without look at us, do they see the hand of Christ quite unmistakably? Does it ever occur to anybody that there is something in our life which is not of the world, but which is a message to the world from Christ? Did you ever, startled by the unusual brightness of a true Christian's life, ask as it were involuntarily, "Whose image and superscription is this?" and feel as you asked it that these features, these characters, could only have been traced by one hand, and that they proclaimed to all the grace and power of Jesus Christ? Christ wishes so to write upon us that men may see what He does for man. He wishes to engrave His image on our nature, that all spectators may feel that it has a message for them, and may crave the same favour. A congregation which is not in its very existence and in all its works and ways a legible epistle, an unmistakable message from Christ to man, does not answer to this New Testament ideal.
Paul claims no part here but that of Christ's instrument. The Lord, so to speak, dictated the letter, and he wrote it. The contents of it were prescribed by Christ, and through the Apostle's ministry became visible and legible in the Corinthians. More important is it to notice with what the writing was done: "not with ink," says St. Paul, "but with the Spirit of the living God." At first sight this contrast seems formal and fantastic; nobody, we think, could ever dream of making either of these things do the work of the other, so that it seems perfectly gratuitous in Paul to say, "not with ink, but with the Spirit." Yet ink is sometimes made to bear a great deal of responsibility. The characters of the τινὲς ("some") in ver. i, were only written in ink; they had nothing, Paul implies, to recommend them but these documents in black and white. That was hardly sufficient to guarantee their authority, or their competence as ministers in the Christian dispensation. But do not Churches yet accept their ministers with the same inadequate testimonials? A distinguished career at the University, or in the Divinity Schools, proves that a man can write with ink, under favourable circumstances; it does not prove more than that; it does not prove that he will be spiritually effective, and everything else is irrelevant. I do not say this to disparage the professional training of ministers; on the contrary, the standard of training ought to be higher than it is in all the Churches: I only wish to insist that nothing which can be represented in ink, no learning, no literary gifts, no critical acquaintance with the Scriptures even, can write upon human nature the Epistle of Christ. To do that needs "the Spirit of the living God." We feel, the moment we come upon those words, that the Apostle is anticipating; he has in view already the contrast he is going to develop between the old dispensation and the new, and the irresistible inward power by which the new is characterised. Others might boast of qualifications to preach which could be certified in due documentary form, but he carried in him wherever he went a power which was its own witness, and which overruled and dispensed with every other. Let all of us who teach or preach concentrate our interest here. It is in "the Spirit of the living God," not in any acquirements of our own, still less in any recommendations of others, that our serviceableness as ministers of Christ lies. We cannot write His epistle without it. We cannot see, let us be as diligent and indefatigable in our work as we please, the image of Christ gradually come out in those to whom we minister. Parents, teachers, preachers, this is the one thing needful for us all. "Tarry," said Jesus to the first evangelists, "tarry in the city of Jerusalem, until ye be endued with power from on high"; it is of no use to begin without that.