You don't get much more authentic than Jesus and His disciples - ALL Jews! However, we have the witness of another Jew, Saul of Tarsus, who adamantly set out, filled with great religious fervor, to stop the spread of theis 'christian heresy'.
Acts 9:1-5, "But Saul, still breathing threats of slaughter against the disciples of the Lord, went to the high priest and asked him for letters to the synagogues at Damascus, that if he found any men or women belonging to this Way (a word used for Christianity), he might bring them in bonds to Jerusalem. And as he went on his journey, it came to pass that he drew near to Damascus, when suddenly a light from heaven shone round about him; and falling to the ground, he heard a voice saying to him, "Saul, Saul, why dost thou persecute me?" And he said, "Who art thou Lord?" And He said, "I am Jesus whom thou art persecuting.""
You think that the fact that J*sus and the disciples were Jewish mean that their teaching couldn't have been heretical? Then that means that Luther couldn't have been a heretic because he was Catholic!
I don't get it. The hypocrisy of Catholics and Orthodox chr*stians is absolutely palpable, yet you don't see it. One minute you're attacking sola scriptura and insisting on an official Biblical interpretation. Then when someone brings up the unpleasant fact that this interpretation was already in existence from Mt. Sinai you suddenly become "simple Southern Baptists" and start "proving" the new testament's claims by merely quoting them!
Bottom line: if there's a tradition, it's from Sinai. If the tradition from Sinai is no longer valid, then no tradition is.
If you support proselytization of Jews, don't pitch a fit when Protestants target you.