Christians attitudes towards Messianic Jews
As I understand it, the Jews are God's chosen people and the Gentiles are grafted into the vine. That makes us equal and part of God's kingdom but we still need to acknowledge the Jews (Messianic Jews). The Messianic Jewish community is growing very rapidly. They are Jews who observe both the Jewish festivals and the whole of the New Testament.
Acceptance of the Gospel
Paul is talking about Israel and the gospel in Romans 10:16-21 and 11:11. The Israelites were given the gospel but did not want it so it was given to the gentiles who accepted it, provoking the Jews to jealousy. It is like a child who has a toy that he has never wanted, his brother takes it and likes it, now the child wants it back.
Israel must be saved before Jesus returns
Peter is talking to the Jews in the temple: "Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord; and he shall send Jesus Christ, which before was preached unto you: ..."(Acts 3:19-20).
Grafting
Romans 11 in order
Paul says that God has not cast away his people, and being himself an Israelite (verses 1-2).
Paul refers to the Old Testament and talks about 7000 Jews who did not worship Baal; "Even so then at this present time also there is a remnant according to the election of grace." (verse 5). These are Messianic Jews of Paul's time.
"What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded..." (verse 7).
Paul is speaking to the Gentiles: "For the firstfruit be holy, the lump is also holy: and if the root be holy, so are the branches. And if some of the branches be broken off, and thou, being a wild olive tree, wert grafted in among them, and with them partakest of the root and fatness of the olive tree; boast not against the branches, but if thou boast, thou bearest not the root, but the root thee. Thou wilt say then, The branches were broken off, that I might be grafted in. Well; because of unbelief they were broken off, and thou standest by faith. Be not highminded, but fear: for if God spared not the natural branches, take heed lest he also spare not thee." (verses 16-21).
God is able to graft the natural branches back in again (verse 23).
Paul uses the olive tree to show how the Jews and Gentiles fit into God's kingdom; the natural branches being the Jews, and the wild branches being the Gentiles. Paul then goes on to say that the Gentiles (wild branches) fit into the good olive tree: "how much more shall these, which be grafted into their own olive tree?" (verse 24). He says this because the Messianic Jews have a better understanding of the Bible than the Gentiles, because it was written to them and their culture and festivals.
In verse 26; Paul says that all Israel shall be saved!
Other Points
There are many references to the Pharisees, and it should be remembered that not all of the Pharisees were unbelievers. The Apostle Paul, for example, was a Pharisee (Philippians 3:5). It's true that there were many unbelieving Pharisees, and they led many other Jews into unbelief, but we should be careful not to overlook the fact that Jesus (Yeshua) and his disciples were also Jews, and indeed in the early days all the church were Jews. They didn't start preaching to the Gentiles until Peter's visit to Cornelius, and even then some of them only preached to the Jews (Acts 11:19). They were given the scriptures and preserved them for all these years. Without the Jewish believers, there would be no Gentile believers, so we should be grateful to them.