Yes, of course, it was effective for some of the Israelites. Jeremiah is predicting a day when the Holy Spirit will indwell the entire nation after ungodliness has been removed from Jacob.
I know you are. But Jeremiah is not talking about the Israelites in general. He is talking about the nation of Israel.
Jeremiah is talking about corporate salvation.
Romans 11:25-29 tells us:
“For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in. And so all Israel shall be saved: as it is written, There shall come out of Sion the Deliverer, and shall turn away ungodliness from Jacob: For this is my covenant unto them, when I shall take away their sins. As concerning the gospel, they are enemies for your sakes: but as touching the election, they are beloved for the fathers' sakes. For the gifts and calling of God are without repentance.”
This is a passage that has confused some Christians over the years. The reason for this revolves around the phrase “all Israel shall be saved.” There are many that deduce corporate salvation for natural Israel from this simple expression. This emanates specifically from within the Premillennialist camp.
But does this passage teach that every single Jew in the future will put their trust in Jesus Christ?
One just has to study Romans 9–11 carefully to see that Paul is actually talking about two Israel’s in his discourse – one natural and the other spiritual, one elect and the other blinded, one true and the other apostate. To miss this is to miss the whole thrust of his teaching.
Dispensationalists fail to notice (or choose to ignore) Paul introductory comments to his thesis in Romans 9:6-13. There, Paul identifies who “all Israel” is:
“For they are not all Israel, which are of Israel: Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called. That is, they which are the children of the flesh, these are not the children of God: but the children of the promise are counted for the seed. For this is the word of promise, At this time will I come, and Sara shall have a son. And not only this; but when Rebecca also had conceived by one, even by our father Isaac; (For the children being not yet born, neither having done any good or evil, that the purpose of God according to election might stand, not of works, but of him that calleth. It was said unto her, The elder shall serve the younger. As it is written, Jacob have I loved, but Esau have I hated.”
He is talking here about an enlightened segment within the overall congregation of natural Israel that know Christ and are redeemed of God. Basically, there is a faithful remnant amongst Israel that have experienced salvation. This is supported by comparing Romans 11:26
“all Israel shall be saved” (future, passive, indicative) to Romans 9:27, which says,
“a remnant shall be saved” (future, passive, indicative).
Is Paul contradicting himself with these two statements? Of course not. He is saying the same thing. Let us be absolutely assured: Paul is definitely not opposing himself, neither is the Holy Spirit, who inspired him to pen this, confused. He is in no way teaching corporate salvation in Romans 11:25-29, as some would suggest, or else he would be reversing everything he has just taught in the preceding verses and chapters of this book (and his other Epistles) in regard to an elect remnant.
These parallel statements correspond with each other and represent the same truth regarding the same company. Not all Israelies are saved, only the election (the chosen).
Contrary to what some end-time “experts” think, salvation was never secured on the grounds of race; it was always by grace through faith. Moreover, the Gospel opportunity in the New Testament is always shown to be open to all nationalities equally; this includes natural Israel.
When one digs a little deeper and analyzes the Premillennial reasoning further one discovers additional inconsistencies and contradictions in their reasoning. Whilst they are adamant that Romans 11:26 should be understood as teaching corporate salvation for every single Jew in Israel in the future, they are unwilling to apply the same standard to the verse before in Romans 11:25 which is speaking about the Gentiles:
“the fulness (or full amount)
of the Gentiles be come in.” They rightly understand this to be applying to a faithful segment of the Gentiles.
Applying the same reasoning in regard to Romans 11:26 to Romans 11:25 would of course render them universalists. It would suggest every single Gentile would be saved before the end. This is the absurdity that Premillennialism produces.
Of course, both statements are speaking about a remnant from amongst the overall natural whole. But Premillennial bias prevents them from having a consistent and objective mode of interpretation.