"For He Himself is our peace, who has made both (Gentile and Jew) one, and has broken down the middle wall of separation, 15 having abolished in His flesh the enmity, that is, the law of commandments contained in ordinances, so as to create in Himself one new man from the two, thus making peace, 16 and that He might reconcile them both to God in one body through the cross, thereby putting to death the enmity. 17 And He came and preached peace to you who were afar off and to those who were near. 18 For through Him we both have access by one Spirit to the Father."
Our access to the Father is "by one Spirit". Additionally, flesh and blood gains nothing in the Kingdom of God.
Christ is neither Jew or Gentile. He is a Spirit Man given a body that is suitable for eternity; not like the flesh He had as Jesus.
If you say "Mary, who is Jewish, was His mother. So He is still Jewish" you are like the Roman Catholics who believe Mary's fleshly inheritance from Adam lives on in the risen Christ. This is idolatry.