|A175 : by Paul Henebury |
Thanks for the question. The answer, I think, comes out of the clear promises within the Abrahamic Covenant (AC) and how Paul relates those elements of the covenant which pertain to the Gentiles to the Church (because in the Church God goes deliberately to the Gentiles). But it is crucial we do not turn a blind eye to what Paul does not say!
You don't need me to tell you that the AC, from the very start, considered Gentiles (Gen. 12:3; 22:18). Thus, if the Apostle zooms in on these promises and applies them to the Church he is doing something which we should all find instinctive. Of course the Gentiles (nations) are in view in the AC! BUT, they are not in view in every specific promise contained in the AC, so Paul picks out only those promises that pertain to the Gentiles and leaves those others which pertain to Israel. Covenant theologians - because they insist on denigrating the OT contexts by reading their interpretations of the NT back into the Old - do not see this. Furthermore, they don't care to see it.
Please note: in Rom. 4:3 Paul cites Gen. 15:6 to prove that Abraham was justified by faith before he was circumcised. Therefore, Abraham is not the father of Israel at that time. For this reason he acts as the exemplar and "father" of all believers (Rom. 4:16). So the part of the AC which deals with the nations is then quoted (Gen. 17:5). It is this which Paul has in mind when he refers to Abraham as "the heir of the world" in v. 13. Please note, Paul is not dealing with the land in that verse! He is dealing with justification by faith. That is what we need to be considered Abraham's "seed" in the sense spoken about in Gal. 3 (which I'll get to presently).
Now, flip over to Rom. 9 where Paul is dealing with the Jewish question (9:1-4, 13, 27 etc.). In v.10 the Apostle speaks about Isaac (not Abraham) as "our father." Who's father is Isaac? Never the church's! Isaac does not have those things spoken about him concerning justification which we read about in Abraham's case. There is no equivalent to Gen. 15:6 in Isaac's case. Hence, in Rom. 9 Paul is speaking mainly about Israel, not the church.
As you say, Paul again uses the OT to prove the truth of God reaching out to Gentiles. It is an OT truth. But, then we get to Galatians 3.
In Gal. 3 he is, of course, speaking about justification by faith again (e.g. Gal. 3:2, 5, 9 etc.). He again cites Gen. 15:6 in v.6. Then, in v.8 he quotes Gen. 22:18. Gen. 22:18 does not contain all the promises housed within the AC; only that which deals with the nations. Now, what does Paul do with it? Does he teach the other promises of land, king, priesthood, fecundity etc. for Israel are past? Not at all. He's not dealing with those things so he doesn't speak of them.
Gal. 3:16 causes a lot of trouble. What are the "promises" he refers to in that passage? Well, the promises to the Gentiles he has been speaking about! How are they realized? Through the "Seed" (singular) of Gen. 22:18 (which he has just quoted) who is Christ. Thus, Gentile believers are of like faith with Abraham and are considered his spiritual sons or seed (Gal. 3:26, 29). All this is quite true and to be expected from what the OT teaches. But it does not mean Abraham's physical seed (Israel) do not have covenant promises awaiting them too! They do. But they must believe (e.g. Deut. 30:6; Isa. 45:17, 19, 25; 46:12-13, etc.). Thus, one does not need to resort to the absurdities of ultra-dispensationalism (the dispensations should not be given such a determinative role in our theologizing. The Bible doesn't do it and we shouldn't. That is, the dispensations have no prescriptive power). But neither do we have to fall into the ignorant error of overlooking pertinent texts on the AC which threaten a "one people of God" theology a la covenant theology. All we need to do is stick with the apostle's argument and note which parts of the AC he is dealing with. I guess God expects us to be able to do that :)
One more thing. The AC contains no redemptive promises. It requires the New Covenant for it to be fulfilled. Hence, Jer. 31:31ff. states this in Israel's case, and Luke 22 & 1 Cor. 11 in the churches case. It is the SAME New Covenant, since it is the same Christ. Thus, any eschatological fulfillment of any biblical covenant goes through Christ and therefore needs the New Covenant in His Blood.
Hope this answers your question.