He has been quoting a mosaic of Old Testament passages from the
Psalms and Isaiah. He regards these as part of 'the law,' which term,
therefore, in his view, here includes the whole previous revelation,
considered as making known God's will as to man's conduct. Every word
of God, whether promise, or doctrine, or specific command, has in it
some element bearing on conduct. God reveals nothing only in order
that we may know, but all that, knowing, we may do and be what is
pleasing in His sight. All His words are law.
But Paul sets forth another view of its purpose here; namely, to
drive home to men's consciences the conviction of sin. That is not
the only purpose, for God reveals duty primarily in order that men
may do it, and His law is meant to be obeyed. But, failing obedience,
this second purpose comes into action, and His law is a swift witness
against sin. The more clearly we know our duty, the more poignant
will be our consciousness of failure. The light which shines to show
the path of right, shines to show our deviations from it. And that
conviction of sin, which it was the very purpose of all the previous
Revelation to produce, is a merciful gift; for, as the Apostle
implies, it is the prerequisite to the faith which saves.
As a matter of fact, there was a far profounder and more inward
conviction of sin among the Jews than in any heathen nation. Contrast
the wailings of many a psalm with the tone in Greek or Roman
literature. No doubt there is a law written on men's hearts which
evokes a lower measure of the same consciousness of sin. There are
prayers among the Assyrian and Babylonian tablets which might almost
stand beside the Fifty-first Psalm; but, on the whole, the deep sense
of sin was the product of the revealed law. The best use of our
consciousness of what we ought to be, is when it rouses conscience to
feel the discordance with it of what we are, and so drives us to
Christ. Law, whether in the Old Testament, or as written in our
hearts by their very make, is the slave whose task is to bring us to
Christ, who will give us power to keep God's commandments.
Another purpose of the law is stated in verse 21, as being to bear
witness, in conjunction with the prophets, to a future more perfect
revelation of God's righteousness. Much of the law was symbolic and
prophetic. The ideal it set forth could not always remain
unfulfilled. The whole attitude of that system was one of
forward-looking expectancy. There is much danger lest, in modern
investigations as to the authorship, date, and genesis of the Old
Testament revelation, its central characteristic should be lost sight
of; namely, its pointing onwards to a more perfect revelation which
should supersede it.