Here is a line of thinking, logical and fundamental. Jesus was not Greek. The name, Jesus, is a twice transliterated word from Hebrew, and it means Salvation,. This is in line with what the angel told Mary, that she should call His name, Salvation, for He shall save His people.
It is true, Salvation was of the lineage of Judah, thus in this sense a Jew, however He is the fulfillment of the promise to Abraham. Abraham was promised his descendants would possess the Gate of their enemies! That Gate can only be Yeshua, Salvation.
Let us proceed a bit further. With the above in mind, this does not make a disciple a Jew, not necessarily. It does not make a dsciple of Yeshua, Salvation, an Israeli either. No, anyone who fundamentally believes the Word, as I believe I do, whould be of the faith of Abraham. Yeshua, that is, Salvation referred to the sons of Abraham, also to the faith of Abraham.
Now, were you truly fundamental, you would research two words, Judah and Israel. Now to the astonishment of all, whoever truly believes Yeshua, Salvation, is also, but by translation, of Judah and of Israel, and why not? We await the capital of the spiritual Israel to be bought down from Yahweh, that being New Jerusalem.
I am by no means saying Christians are not disciples of the Messiah. What I am saying is, logic can be whimsical, yet revealing. Be certain there are shells in that shotgun before defending a theology of mankind with it.