3:19 In view of the foregoing argument, did the Law have any value? Yes, God had several purposes in it. Purpose, not cause, is in view, as is clear in the Greek text.
There have been four primary interpretations of what "because of transgressions"means. First, some take it to mean "to restrain transgressions."103This seems legitimate since all law has a restraining effect. Second, some understand the phrase to mean "to reveal transgressions."This seems valid in view of other statements that Paul made (cf. Rom. 3:20; 4:15; 5:13). Third, it may mean "to provoke transgressions."This, too, seems legitimate. A "Do not touch. Wet paint!"sign on a bench tempts people to touch the bench to see if the paint really is wet. Fourth, some have understood that Paul meant "to awaken a conviction of transgressions."This seems less likely in this context since Paul showed more concern with the objective facts of salvation history than he did with the subjective development of faith in the individual.104
Angels who stood between God and the Israelites mediated the Mosaic Covenant (cf. Deut. 33:2, LXX). Both God and the Jews had responsibilities under the Law. In contrast, God Himself revealed the Abrahamic Covenant, without mediation, in which only God had responsibilities (v. 20; cf. Gen. 15).
"Just as it [the Law] had a point of origin on Mount Sinai, so also it had a point of termination--Mount Calvary."105
Paul clarified that the Law was only a temporary measure designed to function until Christ came.
"The function of the law was to point people to Christ, not to provide for all time the way the people of God should live."106
The Christian Reconstruction movement, headed by Rousas J. Rushdoony, Greg Bahnsen, and Gary North, answers Paul's question, "Why the Law then?"(v. 19) this way. God gave the Mosaic Law to provide a framework for the operation of every nation's government.107
"Reconstructionists anticipate a day when Christians will govern using the Old Testament as the law book"108
Reconstructionism rests on presuppositional apologetics, theonomy (lit. the rule of God), and postmillennialism. Other names for it are the theonomy movement and the Chalcedon school. It is gaining many followers especially among charismatic evangelicals. Its popular appeal is that it claims God wants America and every other nation to function as God intended Israel to function, namely as a theocracy. It fails to make a distinction between God's unique purpose for Israel and His purpose for other nations throughout history.109
3:20 The meaning of this verse has drawn numerous different explanations.110I think Paul probably meant that a mediator (here the angels, v. 19) is necessary when two parties make an agreement in which they both assume responsibilities, as in the reciprocal Mosaic Covenant. However a mediator is not necessary when the covenant is unilateral, as when God made the unconditional Abrahamic Covenant.
3:21-22 Do the Law and the promises contradict each other? Never! God designed them for two different purposes. The purpose of the Law was never to provide justification. It served as a mirror to show people their sinfulness and that they are the slaves of sin. When they realize they cannot save themselves, they will be open to receiving salvation as a gift by faith.
"God always intended to save by faith, apart from law. God gave the law, but he gave it in order that it would condemn all and thus prepare negatively for redemption on the basis of faith (3:22, 24, the purpose clauses conveying God's intention). The law was not given to make alive (3:21)."111
"It rivets upon us the conviction that we cannot be justified by anything we can do. Like the Israelites in Egypt, we are commanded to make bricks without straw, to be perfectly holy when we have none of the makings of holiness--to love God with all our hearts and the neighbor as ourselves when we are without divine charity."112
"A law can lay down what people ought to do, but it cannot give them the power to overcome the temptations to do evil."113
The whole Old Testament (v. 22), not just the Law of Moses (v. 21), showed that people are sinners and incapable of saving themselves.
