I found your website online trying to do some research. Can you please tell me your perspective on Romans 11:25-27 and whom Paul is referring to?
"For I do not desire, brethren, that you should be ignorant of this mystery, lest you should be wise in your own opinion, that blindness in part has happened to Israel until the fullness of the Gentiles has come in. And so all Israel will be saved, as it is written: "The Deliverer will come out of Zion, And He will turn away ungodliness from Jacob; For this is My covenant with them, When I take away their sins." Concerning the gospel they are enemies for your sake, but concerning the election they are beloved for the sake of the fathers. For the gifts and the calling of God are irrevocable. For as you were once disobedient to God, yet have now obtained mercy through their disobedience, even so these also have now been disobedient, that through the mercy shown you they also may obtain mercy" (Romans 11:25-31).
In another letter Paul also speaks of the "mystery":
"For this reason I, Paul, the prisoner of Christ Jesus for you Gentiles-- if indeed you have heard of the dispensation of the grace of God which was given to me for you, how that by revelation He made known to me the mystery (as I have briefly written already, by which, when you read, you may understand my knowledge in the mystery of Christ), which in other ages was not made known to the sons of men, as it has now been revealed by the Spirit to His holy apostles and prophets: that the Gentiles should be fellow heirs, of the same body, and partakers of His promise in Christ through the gospel, of which I became a minister according to the gift of the grace of God given to me by the effective working of His power. To me, who am less than the least of all the saints, this grace was given, that I should preach among the Gentiles the unsearchable riches of Christ, and to make all see what is the fellowship of the mystery, which from the beginning of the ages has been hidden in God who created all things through Jesus Christ; to the intent that now the manifold wisdom of God might be made known by the church to the principalities and powers in the heavenly places, according to the eternal purpose which He accomplished in Christ Jesus our Lord" (Ephesians 3:1-11).
The mystery -- the puzzle not understood in ages past -- was that the Gentiles would become fellow heirs with the Jews in a single body that is known as the church. "For He Himself is our peace, who has made both one, and has broken down the middle wall of separation, having abolished in His flesh the enmity, that is, the law of commandments contained in ordinances, so as to create in Himself one new man from the two, thus making peace, and that He might reconcile them both to God in one body through the cross, thereby putting to death the enmity" (Ephesians 2:14-16).
To accomplish this feat, Paul states that it was necessary for the Jews, as a whole, to reject the gospel to make room for the entrance of the Gentiles. "What then? Israel has not obtained what it seeks; but the elect have obtained it, and the rest were blinded. Just as it is written: "God has given them a spirit of stupor, Eyes that they should not see And ears that they should not hear, To this very day"" (Romans 11:7-8). Paul talks about this same spiritual blindness to the Corinthians. "But their minds were blinded. For until this day the same veil remains unlifted in the reading of the Old Testament, because the veil is taken away in Christ. But even to this day, when Moses is read, a veil lies on their heart. Nevertheless when one turns to the Lord, the veil is taken away" (II Corinthians 3:14-16). The Jews never really understood what their law was about and what it was leading to.
The Jews ignored the fact that God promised salvation to the Gentiles. "All the ends of the world shall remember and turn to the LORD, and all the families of the nations shall worship before You" (Psalms 22:27). Yet we see in Acts that the Jews were a hindrance to the spread of the gospel. They actively opposed its teaching and sought to modify it into form of Judaism. This continued until Jerusalem fell and the Jews became a broken people. "And they will fall by the edge of the sword, and be led away captive into all nations. And Jerusalem will be trampled by Gentiles until the times of the Gentiles are fulfilled" (Luke 21:24). You can see this in Paul's declaration: "Then Paul and Barnabas grew bold and said, "It was necessary that the word of God should be spoken to you first; but since you reject it, and judge yourselves unworthy of everlasting life, behold, we turn to the Gentiles. For so the Lord has commanded us: 'I have set you as a light to the Gentiles, That you should be for salvation to the ends of the earth.'" Now when the Gentiles heard this, they were glad and glorified the word of the Lord. And as many as had been appointed to eternal life believed" (Acts 13:46-48).
It isn't that Gospel wasn't taught to the Gentiles beforehand. Indeed, the message was reaching all the world. "We give thanks to the God and Father of our Lord Jesus Christ, praying always for you, since we heard of your faith in Christ Jesus and of your love for all the saints; because of the hope which is laid up for you in heaven, of which you heard before in the word of the truth of the gospel, which has come to you, as it has also in all the world, and is bringing forth fruit, as it is also among you since the day you heard and knew the grace of God in truth" (Colossians 1:3-6). Yet, it soared after the resistance of the Jews was removed.
In the same way, it isn't that Jews weren't converting to the Gospel both before and after the fall of Jerusalem, but there was a period of time when old traditions held strong sway over the Jews.
However, this reversal of acceptance of the Gospel would not be permanent. God's promise of salvation was for all nations, including the Jews, and His promises are irrevocable. Thus, the time would shortly come where both Jews and Gentiles would equally come into the Kingdom. "For as many of you as were baptized into Christ have put on Christ. There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ Jesus. And if you are Christ's, then you are Abraham's seed, and heirs according to the promise" (Galatians 3:27-29).
This passage is sometimes misquoted to claim that all Jews will be converted to Christianity some day in the future. But just as not all Gentiles came to Christ, there is nothing in this passage to say that all Jews would come to Christ. In fact, in the passage Paul quoted in part, it says: ""The Redeemer will come to Zion, And to those who turn from transgression in Jacob," Says the LORD" (Isaiah 59:20). Notice that the promise is to those who turn from sin. It doesn't guarantee all will turn.