This idea of the "epistle" has taken such a hold of the Apostle's mind, and he finds it so suggestive whichever way he turns it, that he really tries to say too much about it in one sentence. The crowding of his ideas is confusing. One learned critic enumerates three points in which the figure becomes inconsistent with itself, and another can only defend the Apostle by saying that this figurative letter might well have qualities which would be self-contradictory in a real one. This kind of criticism smells a little of ink, and the only real difficulty in the sentence has never misled any one who read it with sympathy. It is this--that St. Paul speaks of the letter as written in two different places. "Ye are our epistle," he says at the beginning, "written _in our hearts_"; but at the end he says, "written not on tables of stone, but on tables that are hearts of flesh"--meaning evidently _on the hearts of the Corinthians_. Of course this last is the sense which coheres with the figure. Paul's ministry wrote the Epistle of Christ upon the Corinthians, or, if we prefer it, wrought such a change in their hearts that they became an epistle of Christ, an epistle to which he appealed in proof of his apostolic calling. In expressing himself as he does about this, he is again anticipating the coming contrast of Law and Gospel. Nobody would think of writing a _letter_ on tables of stone, and he only says "not on stone tables" because he has in his mind the difference between the Mosaic and the Christian dispensation. It is quite out of place to refer to Ezek. xi. 19, xxxvi. 26, and to drag in the contrast between hard and tender hearts. What Paul means is that the Epistle of Christ is not written on dead matter, but on human nature, and that too at its finest and deepest. When we remember the sense of depth and inwardness which attaches to the heart in Scripture, it is not forcing the words to find in them the suggestion that the Gospel works no merely outward change. It is not written on the surface, but in the soul. The Spirit of the living God finds access for itself to the secret places of the human spirit; the most hidden recesses of our nature are open to it, and the very heart is made new. To be able to write _there_ for Christ, to point not to anything dead, but to living men and women, not to anything superficial, but to a change that has reached the very core of man's being, and works its way out from thence, is the testimonial which guarantees the evangelist; it is the divine attestation that he is in the true apostolical succession.[23]
What, then, does Paul mean by the other clause, "ye are our epistle, written on _our_ hearts?" I do not think we can get much more than an emotional certainty about this expression. When a man has been an intensely interested spectator, still more an intensely interested actor, in any great affair, he might say afterwards that the whole thing and all its circumstances were engraved upon his heart. I imagine that is what St. Paul means here. The conversion of the Corinthians made them an epistle of Christ; in making them believers through St. Paul's ministry, Christ wrote on _their_ hearts what was really an epistle to the world; and the whole transaction, in which Paul's feelings had been deeply engaged, stood written on _his_ heart for ever. Interpretations that go beyond this do not seem to me to be justified by the words. Thus Heinrici and Meyer say, "We have in our own consciousness the certainty of being recommended to you by yourselves and to others by you"; and they elucidate this by saying, "The Apostle's _own good consciousness_ was, as it were, _the tablet_ on which this living epistle of the Corinthians stood, and _that_ had to be left unassailed even by the most malevolent." A sense so pragmatical and pedantic, even if one can grasp it at all, is surely out of place, and many readers will fail to discover it in the text. What the words do convey is the warm love of the Apostle, who had exercised his ministry among the Corinthians with all the passion of his nature, and who still bore on his ardent heart the fresh impression of his work and its results.