19 What purpose then does the law serve? It was added because of transgressions, till the Seed should come to whom the promise was made; and it was appointed through angels by the hand of a mediator.
20 Now a mediator does not mediate for one only, but God is one.
What purpose then does the law serve? — if the law cannot procure the gift of the Spirit, v.2, if it does not give evidence of possessing any inherent power, v.5, if no man is justified by it, if no man obtains life by its means, if no one is brought into the enjoyment of blessing by it, vs. 11, 12, 14, then what purpose was it intended to serve? With what object was it given? The question arises here naturally, for it cannot be supposed that God gave this law gratuitously, purposelessly, and yet the apostle had denied to the law every advantage claimed, and left it without any ostensible reason for its existence — Vine, page 191.
added (v.19) = placed beside. The law was given in addition to the promise.
because of (v.19) = to provoke
transgressions (v.19) = breach of the law, to step beyond a fixed point into forbidden territory. The law didn’t make men sinners, but it did make them transgressors. (Romans 5:13; 7:8) Man did not realize his sinfulness under the promise, so the law was given so sin could not be mistaken or confused.
the Seed (v.19) = Christ. The promise is eternal, but the law only continued until Christ came.
appointed (v.19) = ordained, administered. The law, administered by angels (Deuteronomy 33:2; Hebrews 2:2) is inferior to the promise, administered by God.
The object of this section of the apostle’s argument seems to be to demonstrate the inferiority of the old economy, glorious thought it was, to the new, and to this end he enumerates four points of difference:
the law was given in order to justify God in His condemnation of men;
it was a temporary expedient;
it was given through the agency of angels;
it was received by a human mediator.
Whereas:
the gospel of grace, wherein the promise is embodied and potentially fulfilled, is given for the salvation of men;
it is final and permanent;
it is ministered directly by God Himself, apart from angelic agency;
it is received by men, apart from human mediation.
Thus the words of the apostle, written in another connection are true also in this: “If the ministration of condemnation is glory, much rather doth the ministration of righteousness exceed in glory,” 2 Corinthians 3:9. — Vine, page 192-193.
not mediate for one (v.20) — Only where two parties take on mutual obligations is a mediator needed. Two parties — mediator. God is one. The promise was given by one party, God, to Abraham without a mediator. So, again, the law is inferior to the promise.
The very idea of a mediation supposed two persons at least between whom the mediation is carried on. The law, then is of the nature of a contract between two parties, God on the one hand, and the Jewish people on the other. It is valid only so long as both parties fulfill the terms of the contract. It is therefore contingent, and not absolute … Unlike the law, the promise is absolute and unconditional. It depends on the sole decree of God. There are not two contracting parties. There is nothing of the nature of a stipulation. The give is everything, the recipient nothing. — Vine, page 193.
