Romans chapters 9, 10, and 11 have many interpretations. This is my translation and notes of Romans 9:1-5. You may disagree. That is OK. But read and study these verses for yourself.
Romans Chapter 9:1-5
Paul’s Desire For All Israel To Be Saved
1 I tell the truth in Christ. I do not lie. My conscience is also giving witness in the Holy Spirit,
[Chapters 9, 10, and 11 are a parenthesis explaining the purpose and place of Israel. Israel is a chosen/elect nation. Some questions answered: are there any special blessings for the nation of Israel? What is God’s plan for Israel? Did Israel’s failure cause Israel to be unelected by God? Did God’s promises for Israel fail? Why did God choose Jacob instead of Esau? Can anyone resist God’s will? Why didn’t Israel believe? How does one obtain righteousness? Is there a difference between righteousness by the Law and righteousness by faith? Why are Gentiles considered righteous without obeying the Law? Is there any hope for Israel or are they rejected? How is a Jew saved? How can people be aware of the Gospel? The nation of Israel has failed in so many ways; will they be restored? Can believing Gentiles fail the faith? Plus, other questions].
2 That I have great heaviness and continual sorrow in my heart.
3 For I could wish for myself to be cursed from Christ for my brethren according to the flesh,
[Paul is describing his heart thoughts and love for his countrymen, not actually willing to receive God’s curse. The idea of wish is to want something that most likely will never happen. The Greek word for wish is εὔχομαι eúchomai (G2172). It means to wish. See John 15:13].
4 Who are Israelites, to whom [belongs] the adoption, the glory, the covenants, the giving of the law, the [Temple] service, and the promises.
5 Theirs are the fathers and from whom, concerning the flesh, Christ [came] who is God over all, blessed forever. Amen.
[Being an ethnic Jew has many advantages—the adoption (compare Exodus 4:22 and Jeremiah 31:20), the glory (see 1 Kings 8:11 and Isaiah 60:19), the covenants (see Genesis 17:2 and Deuteronomy 29:1), the giving of the Law (see Nehemiah 9:13-14), the service (compare Numbers 3:7-8), the promises (of land, blessings, and Messiah), and Messiah (Jesus, who is a Jew (compare Psalm 45:6-7, Isaiah 9:6, and Micah 5:2). It does not include salvation, for salvation is to those who believe. Salvation by faith is taught in the Old Testament. See Habakkuk 2:4, Genesis 15:6, and Psalm 33:18-22. The Net Bible has this note:
Or “the Christ, who is over all, God blessed forever,” or “the Messiah. God who is over all be blessed forever!” or “the Messiah who is over all. God be blessed forever!” The translational difficulty here is not text-critical in nature, but is a problem of punctuation. Since the genre of these opening verses of Romans 9 is a lament, it is probably best to take this as an affirmation of Christ’s deity (as the text renders it). Although the other renderings are possible, to see a note of praise to God at the end of this section seems strangely out of place. But for Paul to bring his lament to a crescendo (that is to say, his kinsmen had rejected God come in the flesh), thereby deepening his anguish, is wholly appropriate. This is also supported grammatically and stylistically: The phrase ὁ ὢν (ho ōn, “the one who is”) is most naturally taken as a phrase which modifies something in the preceding context, and Paul’s doxologies are always closely tied to the preceding context. For a detailed examination of this verse, see B. M. Metzger, “The Punctuation of Rom. 9:5” Christ and the Spirit in the New Testament, 95-112; and M. J. Harris, Jesus as God, 144-72].