Your argument collapses if the following verse is true.
Galatians 3:28
There is neither Jew nor Greek...
You cannot be a spiritual Jew because the text says there is not a Jew or a Gentile in Christ.
You may have misunderstood Romans 2-11.
You miss the point again
There is no literal blood Jew or Greek when it comes to being a child of God.
God's children are not determined by DNA.
The original children of God was found In Abraham and Jacob who became Israel.
The 12 tribes followed.
Israel mean child of God or prince of God.
It can also mean
"one who wrestles or struggles with God".
The book of Romans Is clear that God does not distinguish between races. We are Abraham's children through Christ.
Mat 3:9 And think not to say within yourselves, We have Abraham to
our father: for I say unto you, that God is able of these stones to raise up children unto Abraham. Even children of God.
Mat 5:9 Blessed
are the peacemakers: for they shall be called the children of God.
Luk 20:36 Neither can they die any more: for they are equal unto the angels; and are the children of God, being the children of the resurrection.
Rom 8:16 The Spirit itself beareth witness with our spirit, that we are the children of God:
17 And if children, then heirs; heirs of God, and joint-heirs with Christ; if so be that we suffer with
him, that we may be also glorified together.
Eph 3:6 That the Gentiles should be fellowheirs, and of the same body, and partakers of his promise....
Gal 3:28-29 28 There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus. 29 And if ye
be Christ's, then are ye Abraham's seed, and heirs according to the promise.
There is neither male nor female......
I still think people are born one or the other physically.
Paul is speaking about the spiritual regulations or criteria to being a child of God.