"But he [is] a Jew, which is one inwardly; and circumcision [is that] of the heart, in the spirit, [and] not in the letter; whose praise [is] not of men, but of God." (Romans 2:29) "Not as though the word of God hath taken none effect. For they [are] not all Israel, which are of Israel:" (Romans 9:6)
"That is, They which are the children of the flesh, these [are] not the children of God: but the children of the promise are counted for the seed. For this [is] the word of promise, At this time will I come, and Sara shall have a son." (Romans 9:8,9)
"For there is no difference between the Jew and the Greek: for the same Lord over all is rich unto all that call upon him." (Romans 10:12) "For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in.
"And so all Israel shall be saved: as it is written, There shall come out of Sion the Deliverer, and shall turn away ungodliness from Jacob: For this [is] my covenant unto them, when I shall take away their sins. As concerning the gospel, [they are] enemies for your sakes: but as touching the election, [they are] beloved for the fathers' sakes.
"For the gifts and calling of God [are] without repentance. For as ye in times past have not believed God, yet have now obtained mercy through their unbelief: Even so have these also now not believed, that through your mercy they also may obtain mercy. For God hath concluded them all in unbelief, that he might have mercy upon all." (Romans 11:25-32)
"Now I say that Jesus Christ was a minister of the circumcision for the truth of God, to confirm the promises [made] unto the fathers: And that the Gentiles might glorify God for [his] mercy; as it is written, For this cause I will confess to thee among the Gentiles, and sing unto thy name.
"And again he saith, Rejoice, ye Gentiles, with his people. And again, Praise the Lord, all ye Gentiles; and laud him, all ye people. And again, Esaias saith, There shall be a root of Jesse, and he that shall rise to reign over the Gentiles; in him shall the Gentiles trust. Now the God of hope fill you with all joy and peace in believing, that ye may abound in hope, through the power of the Holy Ghost." (Romans 15:8-13)
According to Acts 15:14 all people were Gentiles until Abraham was chosen by God to be the Father of people for His name. "Simeon hath declared how God at the first did visit the Gentiles, to take out of them a people for his name." (Acts 15:14) This Scripture moves into the future, stating that Jesus will return and rebuild the temple out of the ruins.
"And to this agree the words of the prophets; as it is written, After this I will return, and will build again the tabernacle of David, which is fallen down; and I will build again the ruins thereof, and I will set it up: That the residue of men might seek after the Lord, and all the Gentiles, upon whom my name is called, saith the Lord, who doeth all these things.
"Known unto God are all his works from the beginning of the world. Wherefore my sentence is, that we trouble not them, which from among the Gentiles are turned to God:" (Acts 15:15-19) In Hebrew "Yisrael" #3478 is derived from #8280 + #410. He will rule as God; Jisrael is a symbolical name of Jacob; also (typically) of his posterity: - Israel. #8280
Sarah: a prim root: to prevail - have power (as a prince) and #410 el; short, from 352; strength; as adj. might; especially the Almighty (but used also of any Deity): God x goodly x great. #352 'ayil, derived from #193 is strength a chief (politically) also a ram, oaktree, lintel, etc. 193 'uwl means to twist, be strong, the body (as being rolled together) powerful and mighty. In Greek #2474 Israel adopted name of Jacob including his descendents Israel.
Israel is not genetically (physically) different from Gentiles, but they are spiritually different. Isaac was a son by a supernatural event. Abraham and Sarah were both unable to have children. Isaac was a child of a miracle and studying his ancestary, he wasn't the only one. Other women were also barren and God had to intervene. God has been personally involved with his chosen people and it is the reason they have survived against all odds. Many are still willing to die for the writings of the Old Testament.
Since believing Jews and Gentiles who are Jesus's bride are in Him and He is in them. Jesus is a Jew, wouldn't we become one with a Jew and also become part of the spiritual Israel. In God's eyes Israel is not a place but His people separated for His purpose. Satan has permeated the world with a sense of hatred for the Jews which keeps us separated from God. God wants us to love Israelis because they are His chosen children and ultimately can't do wrong and will inherit. There was a reason Jesus was born of a Jewish virgin.
Her make up was different from Gentiles. In the physical, Jesus was 100% man and was tempted to become King of this world before His time. He was compassionate and easily moved to give people what they wanted. One has to come to the conclusion that we will also be Israel and be part of the New Jerusalem afterthe 1000 year Millennium, by circumcision of the heart from a spiritual point of view, not physical.