While working through the middle chapters of Galatians, it is important to keep in mind that Paul is speaking in terms of God’s covenant purposes. This means:
-The issue here is not so much “how can I be saved?” but “what are God’s covenant plans for Israel and the Gentiles in Christ?”
-And of course the basis for any discussion of God’s covenant promises is the promise to Abraham (Gen. 12:1-13).
While Paul was dealing with a specific challenge here in Galatians, there are many similarities between Gal. 3-4 and Rom. 4.
-Both emphasize the fundamental basis of the promise to Abraham in terms of faith.
-Both argue that Abraham is the father of both Jews and Gentiles.
This section hinges on the timing and scope of God’s promise to Abraham.
15 To give a human example, brothers:
Paul begins with a simple observation about human covenants (or wills or testaments). Once a covenant has been made, it cannot be changed.
even with a man-made covenant, no one annuls it or adds to it once it has been ratified.
This serves as a key point regarding the relationship of the Law of Moses to the promise to Abraham. Whatever the purposes of the Law, it could not change the fundamental character of the promise to Abraham.
16 Now the promises were made to Abraham and to his offspring.
Paul’s argument here hinges on the word used in Gen. 15:5, “offspring” (“seed,” KJV).
It does not say, “And to offsprings,” referring to many, but referring to one, “And to your offspring,” who is Christ.
Paul says that the promise was to Abraham’s “offspring” – one, not “offsprings” – many.
Many have interpreted this to mean that the promise to Abraham was only about one person, Christ, and not Isaac and the rest of his descendants. There are two problems with this interpretation:
1) The word “offspring” is a collective noun, like “seed.” It implies a plural, which Gen. 15:5 makes explicit, where Abraham’s “offspring” will be like the stars of the heavens.
2) Such an interpretation is at odds with the obvious meaning of the “seed” or “offspring”promises of Genesis.
A better interpretation is to focus on the collective nature of “offspring” and the sense in which the NT speaks of our incorporation into Christ.
-In 3:29 Paul identifies Abraham’s “offspring,” those who are Christ’s. Yet in 3:19 he seems to refer to Jesus as “the offspring.” How can it be both?
-In 3:28 he says that Jew and Gentile are one “in Christ.”
-And in 3:26-27 he says we become one “in Christ” through faith and in baptism.
Therefore, what Paul means in 3:16 is this: God did not promise Abraham multiple families, but one family. And “in Christ” there is one family, in fulfillment of this promise. And that is why Paul can say at the end of 3:16 that that offspring “is Christ,” because it is only in Christ that we can be included in Abraham’s family.
17 This is what I mean: the law, which came 430 years afterward, does not annul a covenant previously ratified by God, so as to make the promise void.
Now Paul ties in his “human example.” The Law came 430 years after the promise to Abraham (Ex. 12:40-42). Since it came centuries later, it cannot invalidate the promise to Abraham.
18 For if the inheritance comes by the law, it no longer comes by promise; but God gave it to Abraham by a promise.
Therefore, those who say we must come to God on the basis of the Law in order to receive the promises (what Paul here and elsewhere calls our “inheritance” – 3:29; 4:1; 4:7; 4:30) are mistaken, since as Paul previously argued, Abraham’s promises are received by faith (3:6-9). This is very similar to Paul’s argument in Rom. 4:9-17.
19 Why then the law?
As in Romans, Paul now counters the possible charge that he is speaking against the Law of Moses.
It was added because of transgressions,
This could mean:
-It was added to reveal what behaviors God considered sinful (Rom. 7:7-10).
-It was added to make Israel’s sinfulness obvious by leading to even more sin (perhaps the point of Rom. 5:20).
-It was added to provide a remedy for sin to allow the people to remain in fellowship with God (Heb. 9:13).
until the offspring should come to whom the promise had been made,
Whichever is the case, the main point is that the Law was “added” to something that had been in place centuries before, the promise, and that it was not to be permanent. It would last only “until the offspring should come.”
and it was put in place through angels by an intermediary.
Paul seems to be making a contrast between the giving of the Law, which involved two levels of mediation – Moses and the angels (see Acts 7:53; Heb. 2:2), versus the promise to Abraham, which came directly from God to Abraham.
20 Now an intermediary implies more than one, but God is one.
“More than one” what?
One possibility is more than one party is involved in making the covenant, which ties in well with the previous point about the Law of Moses. The REB translates this: “But an intermediary is not needed for one party acting alone.” And since “God is one,” the promises to Abraham is more consistent with God’s nature than the Law of Moses.
Another possibility is that Paul means a mediator implies “more than one nation.” In other words, since God was only giving the Law to Israel, He needed a mediator to go to Israel only. This would be similar to the point in Rom. 3:29-30.
21 Is the law then contrary to the promises of God? Certainly not!
Paul is eager to maintain the validity of the Law in terms of doing what it was intended. God intended to save mankind through the promise on the basis of faith. The Law carried out an important part in bringing that purpose to completion.
For if a law had been given that could give life, then righteousness would indeed be by the law.
The Law itself could not save sinful man; it only made man’s sinfulness worse (see 2 Cor. 3:6).
22 But the Scripture imprisoned everything under sin,
Cf. Rom. 7:7-12; 11:32.
so that the promise by faith in Jesus Christ might be given to those who believe.
Just as it was to Abraham.