[Uri’el-2012]

Consider that the word “Jew” is the English transliteration
of Hebrew Y˒hudi, from the root “yadah,” which means
“to give thanks, to praise, to confess openly and freely.”
To be a true Jew is to be someone who gives thanks to God,
praises God, and confesses God, his Word, his truth
and his love, openly and freely, who is in a close
relationship with him

Stern, D. H. (1996, c1992). Jewish New Testament Commentary
: A companion volume to the Jewish New Testament (electronic
ed.) (Lk 15:15). Clarksville: Jewish New Testament Publications.

shalom b'SHEM Yah'shua HaMashiach

[one Lord one faith one baptism]

according to Paul, the true Jew is one who believes in Jesus Christ. this is why the Church is the Israel of God.
if you belong to Christ, you are an heir to the promises made to Abraham. if you reject Christ, you will die in your sins.