Jesus has some interesting (and harsh) words about who are truly Abraham's children and who are "sons of God"
31 So Jesus was saying to those Jews who had believed Him, “If you continue in My word, then you are truly My disciples; 32 and you will know the truth, and the truth will set you free.” 33 They answered Him, “We are Abraham’s descendants and have never been enslaved to anyone; how is it that You say, ‘You will become free’?”
34 Jesus answered them, “Truly, truly I say to you, everyone who commits sin is a slave of sin. 35 Now the slave does not remain in the house forever; the son does remain forever. 36 So if the Son sets you free, you really will be free. 37 I know that you are Abraham’s descendants; yet you are seeking to kill Me, because My word has no place in you. 38 I speak of the things which I have seen with My Father; therefore you also do the things which you heard from your father.”
39 They answered and said to Him, “Abraham is our father.” Jesus *said to them, “If you are Abraham’s children, do the deeds of Abraham. 40 But as it is, you are seeking to kill Me, a man who has told you the truth, which I heard from God; this Abraham did not do. 41 You are doing the deeds of your father.” They said to Him, “We were not born as a result of sexual immorality; we have one Father: God.” 42 Jesus said to them, “If God were your Father, you would love Me, for I came forth from God and am here; for I have not even come on My own, but He sent Me. 43 Why do you not understand what I am saying? It is because you cannot listen to My word. 44 You are of your father the devil, and you want to do the desires of your father. He was a murderer from the beginning, and does not stand in the truth because there is no truth in him. Whenever he tells a lie, he speaks from his own nature, because he is a liar and the father of lies. 45 But because I say the truth, you do not believe Me. 46 Which one of you convicts Me of sin? If I speak truth, why do you not believe Me? 47 The one who is of God hears the words of God; for this reason you do not hear them, because you are not of God.”
One other quick point...
The Church is the continuation of the faithful remnant of Israel
The head of the Church is the Jewish Messiah and the King of the Jews
The 12 Apostles were Jews.
And the very first Christians were also Jews.
So the Church has NOT REPLACED Israel.
The Church is the ongoing continuation of the faithful remnant of Israel.
As Galatians 3 tells us...
Anyone who puts their faith in the Jewish Messiah and the King of the Jews becomes "Abraham's seed" and is grafted into the True Israel of God (Romans 11).