Among the Christians of the first age, no one so thoroughly appreciated the newness of Christianity, or was so immensely impressed by it, as St. Paul. The difference between the earlier dispensation and the later, between the religion of Moses' disciples and the religion of believers in Jesus Christ, was one that could hardly be exaggerated; he himself had been a zealot of the old, he was now a zealot of the new; and the gulf between his former and his present self was one that no geometry could measure. He had lived, after the straitest sect of the old religion, a Pharisee; touching the righteousness which is in the law he could call himself blameless; he had tasted the whole bitterness of the legalism, the formality, the bondage, in which the old covenant entangled those who were devoted to it in his days. It is with this in his memory that he here sets the old and the new in unrelieved opposition to each other. His feeling is like that of a man who has just been liberated from prison, and whose whole mind is possessed and filled up with the single sensation that it is one thing to be chained, and another thing to be free. In the passage before us, this is all the Apostle has in view. He speaks as if the old covenant and the new had nothing in common, as if the new, to borrow Baur's expression, had merely a negative relation to the old, as if it could only be contrasted with it, and not compared to it, or illustrated by it. And with this restricted view he characterises the old dispensation as one of letter, and the new as one of spirit.[25] Speaking out of his own experience, which was not solitary, but typical, he could truly speak thus. The essence of the old, to a Pharisee born and bred, was its documentary, statutory character: the law, written in letters, on stone tablets or parchment sheets, simply confronted men with its uninspiring imperative; it had never yet given any one a good conscience or enabled him to attain to the righteousness of God. The essence of the new, on the other hand, was spirit; the Christian was one in whom, through Christ, the Holy Spirit of God dwelt, putting the righteousness of God within his reach, enabling him to perfect holiness in God's fear. The contrast is made absolute, _pro tem_. There is no "spirit" in the old at all; there is no "letter" in the new. This last assertion was more natural then than now; for at the time when Paul wrote this Epistle, there was no "New Testament of our Lord and Saviour Jesus Christ" consigned in documents and collected for the use of the Church. The Gospel existed in the world, not at all in books, but only in men; all the epistles were living epistles; there was literally no letter, but only spirit.
This, doubtless, is the explanation of the blank antithesis of the old covenant and the new in the passage before us. But it is obvious, when we think of it, that this antithesis does not exhaust the relations of the two. It is not the whole truth about the earlier dispensation to say that, while the new is spiritual, it is not. The religion of the Old Testament was not mere legalism; if it had been, the Old Testament would be for us an unprofitable and almost an unintelligible book. That religion had its spiritual side, as all but utterly corrupt religions always have; God administered His grace to His people through it, and in psalms and prophecies we have records of their experiences, which are not legal, but spiritual, and priceless even to Christian men. Nor would Paul, under other circumstances, have refused to admit this; on the contrary, it is a prominent element in his teaching. He knows that the old bears in its bosom the promise of the new, a sum of promises that has been confirmed and made good in Jesus Christ (chap. i. 20). He knows that the righteousness of God, which is proclaimed in the Gospel, is witnessed to by the law and the prophets (Rom. iii. 21). He knows that "the law," even, is "spiritual" (Rom. vii. 14). He knows that the righteousness of faith was a secret revealed to David (Rom. iv. 6 f.). He would probably have agreed with Stephen that the oracles received and delivered by Moses in the wilderness were "living" oracles; and his profound mind would have thrilled to hear that great word of Jesus, "I am not come to destroy, but to fulfil." Had he lived to a time like ours, when the Gospel also has been embodied in a book, instead of using "letter" and "spirit" as mutually exclusive, he would have admitted, as we do, that both ideas apply, in some sense, to both dispensations, and that it is possible to take the old and the new alike either in the letter or in the spirit. Nevertheless, he would have been entitled to say that, if they were to be characterised in their differences, they must be characterised as he has done it: the mark of the old, as opposed to the new, is literalism, or legalism; the mark of the new, as opposed to the old, is spirituality, or freedom. They differ as law differs from life, as compulsion from inspiration. Taken thus, no one can have any difficulty in agreeing with him.