2 Peter 3:15-16
15 Bear in mind that our Lord’s patience means salvation, just as our dear brother Paul also wrote you with the wisdom that God gave him. 16 He writes the same way in all his letters, speaking in them of these matters. His letters contain some things that are hard to understand, which ignorant and unstable people distort, as they do the other Scriptures, to their own destruction.
John 3:1-3
1 Now there was a Pharisee, a man named Nicodemus who was a member of the Jewish ruling council. 2 He came to Jesus at night and said, “Rabbi, we know that you are a teacher who has come from God. For no one could perform the signs you are doing if God were not with him.” 3 Jesus replied, “Very truly I tell you, no one can see the kingdom of God unless they are born again.”
Romans 9:3-8
3 For I could wish that I myself were cursed and cut off from Christ for the sake of my people, those of my own race, 4 the people of Israel. Theirs is the adoption to sonship; theirs the divine glory, the covenants, the receiving of the law, the temple worship and the promises. 5 Theirs are the patriarchs, and from them is traced the human ancestry of the Messiah, who is God over all, forever praised! Amen. 6 It is not as though God’s word had failed. For not all who are descended from Israel are Israel. 7 Nor because they are his descendants are they all Abraham’s children. On the contrary, “It is through Isaac that your offspring will be reckoned.” 8 In other words, it is not the children by physical descent who are God’s children, but it is the children of the promise who are regarded as Abraham’s offspring.
Romans 2:28-29
28 A person is not a Jew who is one only outwardly, nor is circumcision merely outward and physical. 29 No, a person is a Jew who is one inwardly; and circumcision is circumcision of the heart, by the Spirit, not by the written code. Such a person’s praise is not from other people, but from God.
According to Scripture Peter said Paul said things that can be hard to understand which ignorant and unstable ppl distort. Paul said "All Israel will be saved" He also says that not all from Israel are Israel nor because they come from Abraham are they his descendants. Jesus Told Nicodemus a Jewish teacher for Israel that no one can enter God's kingdom without being born-again. From the scriptures, we can make the conclusion that all Israel being saved would mean all the true Israelites in Christ are Israel and will be saved, Messianic born-again jews who are of the natural branch along with those grafted in and adopted as jews in Christ make up Israel.