“Once you convert out, you are no longer a Jew”
Messianic Jews haven’t “converted out” as you say, rather they have only embraced and are following the Jewish Messiah that the Hebrew Prophets prophesied of.
If Gentiles brought a Man to Israel and said this is the *Messiah* believe in him, and if they did, then I can see them no longer being *Jews*
It was the *Jews* that brought fourth another *Jew* to the Pagan Gentile Nations and said..
This is the *Lamb of GOD who takes away the Sins of the World*
and PRaise GOD that the Jews did! as we are grafted into the Family of the one true Living GOD!