Or “shut up” means that it held them under sin, as in bonds, in a kind of prison. Then “Scripture” will mean the Old Testament institution, handed down in writing from God and laid upon the Jews as a yoke.
For the center of the Old Testament Scripture is the law given through Moses. The books preceding it are an introduction to it, and the prophetic writings following it are its explanation.
Thus “Scripture shut up” will mean the same as: the law shut all under sin. It shut up all, that is, all who were under the law without exception.
This will correspond directly to the preceding thought. If the law could give life, it would replace the promise and give righteousness. But, he says, not only does it not do this. On the contrary, it keeps all under sin as in confinement.
It demands: do not do this, do not touch that, or be such and such. But it gives no strength for this. All acknowledge the obligation of its demands, yet all see that they are guilty before it at every point.
They are guilty through the law, and they cannot free themselves from guilt by means of the law. This is how the law, Scripture, shut all under sin. It held all in the consciousness of their sinfulness, and therefore of judgment and of having no answer.
Yet this consequence of the law was not at all for evil and destruction, but for salvation. God Himself established it so that, through the feeling of self-preservation implanted by God in our nature, He might lead those under the law to the true path of salvation.
For who is his own enemy? Seeing that the law only brings one into sinfulness and deepens the consciousness of all-sided sinfulness, everyone under the law was thereby moved to seek deliverance from sinfulness.
How then? By throwing off the yoke of the law? That would be still worse. No. By directing a hopeful gaze to Him to Whom the law pointed as a shadow of things to come, and Whom the Prophets portrayed.
So it was until the coming of this Promised One. After His coming, one must cleave by faith to Him alone and receive life from Him. The law did not give this life. It only intensified thirst for it. And of course the law must now be left, since it has already fulfilled its temporary service.
This precise meaning is contained in the Apostle’s words: “that the promise by faith in Jesus Christ might be given to those who believe.” Therefore, he says, the law shut all under sin, so that when the Deliverer came, all might hasten to Him.
Before that moment, all were to test every possible means of self-correction and self-justification. They were to be palpably convinced that nothing is strong enough to give us this good, not even the law given by God.
It was reserved for faith in Jesus Christ and is given to believers by it alone. But in this lies the essence of the promise. Consequently, the promise itself is fulfilled only by faith.
The promise is the blessing of Abraham, consisting in the reception of the Spirit of grace through faith in the Lord. This grace regenerates, gives new life in Christ Jesus, and sanctifies.
“The promise by faith is given to those who believe.” Here there is no tautology, but different meanings of faith. The words “by faith in Jesus Christ” signify the whole New Covenant institution, the entire economy of salvation in the Lord Jesus Christ.
They signify all the spiritual blessings that He obtained for men and entrusted to His holy Church. He means to say that the promise is fulfilled not by the Old Covenant, but by the New.
The words “given to those who believe” point to the personal faith of each Christian. By it he is counted worthy of the blessings with which the Lord Jesus Christ enriches him.
The one who hears the Gospel believes. The believer is baptized, and in baptism by water and the Spirit is born for a new life in Christ Jesus. He begins to live this life in undoubting hope.
He trusts that He Who began this work in him will also bring it to completion. Of course, this requires all possible attention, zeal, and labor on his own part.
From everything the Apostle has said, it followed that the law is in no way against the promises. On the contrary, it both kept those under the law for the promise and prepared them for its worthy reception.
Saint Chrysostom expresses the Apostle’s thought thus: “God gave the Jews a law that would reveal their wounds and move them to seek the physician. The word ‘shut up’ means the same as convicted, and, having convicted, held them in fear. Do you see that the law was given not only not ‘against the promises of God,’ but even for the sake of the promises? If the law had claimed for itself the work and authority of justification, then it would rightly have been said of it that it was contrary to the promises. But when it serves another and does everything for another, how is it contrary to the promises of God? If the law had not been given, all would have sunk into lawlessness, and no one of the Jews would have listened to Christ. But now, when the law was given, it brought a double benefit. First, it guided those who attended to it toward such virtue as was within their power. Second, it awakened in each person the consciousness of his sins, which especially disposed them to seek the Son of God.”