The New Testament makes it evident a "real" Jew is someone who has believed on the Lord Jesus Christ/has been "born again", regardless if they're of Jewish descent.
- NOT ALL ISRAEL ARE OF ISRAEL -
“... They are not all Israel who are descended from Israel ...”
Romans 9:6, Legacy Standard Bible
“... He is a Jew who is one inwardly; and circumcision is that which is of the heart, by the Spirit, not by the letter ...”
Romans 2:29, LSB
- JEWS OF SATAN -
“... Those who say they are Jews and are not, but are a synagogue of Satan”
Revelation 2:9, LSB
“ [Jesus speaking to certain Jews] You are of your father the devil...”
John 8:44, LSB
- BECOME A CHILD OF GOD -
“... As many as received Him [JESUS CHRIST], to them He gave the right to become children of God, even to those who believe in His name ...”
John 1:12, LSB