All the scriptures Calvinists use to try to prove their beliefs are actually passages explaining how the Gentiles come into salvation.
Jews are God’s first people, and salvation had to be an offering to the Jews firstly.
In addition, God had hardened many of the Jews.
They did not believe, and they were hardened. Gentiles grafted in when Jews were hardened and cut off.
The elect are the people who believe. The Gentiles obtained what Israel sought so earnestly (by works). We are saved by grace and not of by works. The Jews had the Law to which they worked. Paul says, “I have great sorrow and unceasing anguish in my heart. For I could wish that I myself were cursed and cut off from Christ for the sake of my brothers, those of my own race, the people of Israel. Theirs is the adoption as sons; theirs the divine glory, the covenants, the receiving of the law, the temple worship and the promises. Theirs are the patriarchs, and from them is traced the human ancestry of Christ, who is God over all, forever praised! Amen.” (Romans 9:1-5)
The Remnant of Israel
Romans 11:1 I ask then: Did God reject his people? By no means! I am an Israelite myself, a descendant of Abraham, from the tribe of Benjamin. 2God did not reject his people, whom he foreknew. Don’t you know what the Scripture says in the passage about Elijah—how he appealed to God against Israel: 3″Lord, they have killed your prophets and torn down your altars; I am the only one left, and they are trying to kill me”? 4And what was God’s answer to him? “I have reserved for myself seven thousand who have not bowed the knee to Baal.” 5So too, at the present time there is a remnant chosen by grace.6And if by grace, then it is no longer by works; if it were, grace would no longer be grace. 7What then? What Israel sought so earnestly it did not obtain, but the elect did. The others were hardened,
Again, the elect are the people who believe in Jesus. We believe in Jesus, and this believing Jesus saves us. That is God’s grace. The people who would not believe in Jesus, they are the people who were hardened for not believing.