Whoever wants to become and be a Christian cannot do so according to worldly organization or conditions!
Yeshua: end & new beginning!
The one true God YHWH sent us Christ, John 17:3, and thus ended the reign of the Jewish priestly order; for Israel and the rest of the world. At the same time, from His Resurrection and the Outpouring of God's Spirit, the possibility began to become a Christian personally and directly, and to be organized by God who is a Spirit, John 4:24.
"This is eternal life: that they may know You, You, the only true God, and Christ Yeshua whom You have sent," John 17:3
"God is a Spirit," John 4:24
Christ has no earthly bosses
The Heavenly High Priest Yeshua has no bosses or "tasters" above him who dictate the (church) service, nor any better followers because of culture (Jewish) or language skills (Hebrew or Greek, for example). On the contrary, in fact. If culture, background or language skills had been the starting point, Christ would not have been crucified by those of his own earthly origin, and if Scripture had truly been understood and carried out as intended, God might not have sent him to us in the first place.
"Yeshua, through whose mediation a new covenant has been established and whose shed blood speaks of something better than that of Abel.", Heb 12:24
"When He (GOD) speaks of a new covenant, He has thereby declared the first obsolete," Heb 8:13; read Heb 8:1-13 yourself.
Christ embodies a New Covenant (Heb 12:24), through which the old is past (Heb 8:13) and you yourself can only come to God through him (baptism of faith, Gal 3:27, Acts 19:5) (prayer with the laying on of hands following baptism, Acts 19:6) and thus simultaneously receive the Gifts of the Spirit as God determines.
"Baptism has united you all with Christ; you have put on Christ as a garment," Gal 3:27.
"Paul laid his hands on them, and the Holy Spirit came upon them. They spoke in strange tongues and prophesied," Acts 19:6.
Every Christian is thus personally a temple in Christ containing God's Spirit and equipped with the Spiritual Tools to be a servant (Rev 1:1) of God and of Christ, just as Christ is a servant of God in that same working unity.
"The revelation of Christ Yeshua, which was given to him by God to show his servants what must soon happen. This revelation he made known to his servant John by sending him his angel," Rev 1:1.
In this way, every person is personally organized in a Heavenly manner by God because of the spiritual connection, His Voice in your life, and the Gifts of the Spirit that you deploy in the world around you; thus leading to "growth" or Fruit of the Spirit. Only with that Fruit, resulting from the personal use of the personally received Gifts of the Spirit, do you receive eternal life, Christ tells us in Matthew chapter 25; without that Fruit, you are eternally lost. Christians, however, are also still tested.
Thus, every Christian is personally responsible and actively engaged with the Gifts linked to God and with Christ as their Lord and King!
"You are therefore no longer strangers who have no rights, but fellow citizens of the people of God, members of his family. You are built on the foundation laid by the apostles and the prophets; the cornerstone is Christ Yeshua himself. To him the whole building owes its solid construction and through him it grows into a holy temple. In unity with him you too are being built up into a spiritual dwelling place for God." (Eph 2:18-22).
However, whoever prefers worldly origins, culture, or organization grows into the corresponding bad fruit of the world. Simply because he/she chose against God's new covenant, against how one is connected to God as a Christian, and against actively going out with the Spirit and Gifts to grow into the Fruit of the Spirit.
Jews get a choice in due course
Paul explains that Judaism (and Jewish Messianism) has been given a stupor spirit by God, which will be taken away as soon as the Christians from among the Gentiles have entered into God to a significant extent through Christ. From that moment on, Jews too can choose for- or against Christ. So being Jewish is not a starting point for becoming a Christian, nor is it the end point!
Rather, get to know Christ and build a relationship with him!