Look at Romans chapter 11 where Paul talks about the olive tree and olive branches.
In Christianity a Jew doesn't become a Gentile, and a Gentile doesn't become a Jew. But they don't need to. Because whether one is Jewish or Gentile, in Jesus all are one, a new people.
The olive tree has both natural branches and wild branches which were grafted on--but all drink of the same nourishment from the root. The natural branches which were pruned, and wild branches which are not grafted suffer the same problem--they are not connected to the life-giving root of the olive tree.
Whether a natural or wild grafted branch, the two are the same when connected to the root.
Whether a natural or wild branch which is separated from the root, neither has life unless they are connected and restored to the root.
Being a Jew or being a Gentile isn't what matters.
Jesus Christ is what matters.
Has God forsaken those Jews who are not in Christ? No.
Has God neglected those Gentiles who are not in Christ? No.
For God has consigned all to disobedience in order that He might have mercy on all (Romans 11:32); for the Gospel is the power of God to save all who believe, the Jew first and also the Gentile (Romans 1:16). For in this Gospel is the righteousness of God, from faith to faith, so that the righteous live by faith (Romans 1:17). Circumcision is nothing and uncircumcision is nothing; but Christ is everything.
So there is one People, one Church, one Israel--in the Messiah. For where the two (Jew and Gentile) were formerly strangers, the both are now one.
-CryptoLutheran
I agree as according to Galations 3:27-29:
27 for all of you who were baptized into Christ have clothed yourselves with Christ. 28 There is neither Jew nor Gentile, neither slave nor free, nor is there male and female, for you are all one in Christ Jesus. 29 If you belong to Christ, then you are Abraham’s seed, and heirs according to the promise.
According to the following passages God still refers to His followers as Jews...
Revelation 2:9:
I know your afflictions and your poverty—yet you are rich! I know about the slander of those who say they are Jews and are not, but are a synagogue of Satan.
Revelation 3:9:
9 I will make those who are of the synagogue of Satan, who claim to be Jews though they are not, but are liars—I will make them come and fall down at your feet and acknowledge that I have loved you.
He also refers to them as the Israel of God...
Galatians 6:16:
16 Peace and mercy to all who follow this rule—to[
a] the Israel of God.
Ephesians 2:12:
12 remember that at that time you were separate from Christ, excluded from citizenship in Israel and foreigners to the covenants of the promise, without hope and without God in the world.
Hebrews 8:8:
8 But God found fault with the people and said:
“The days are coming, declares the Lord,
when I will make a new covenant
with the people of Israel
and with the people of Judah.
Hebrews 8:10:
This is the covenant I will establish with the people of Israel
after that time, declares the Lord.
I will put my laws in their minds
and write them on their hearts.
I will be their God,
and they will be my people.