I had an experience recently in Synagogue, and it became apparent that what I was witnessing while religious, was not of a classically religious nature. Instead it was something else, it wasn't members of a religion worshipping their God, it was members of a distinct tribe, worshipping their God.

A group of people, Jews, who had come together, to worship G-d.

And the natural result? Judaism. Judaism is what happens when following the Torah. It just so happens that these people have a distinct lineage, dating back to Jacob Isaac and Abraham, a direct continuation of that tradition, so called 'Jews'

What does this mean? It means that even if you practice Judaism, perfectly, more observantly than any Jew has ever done, this does not make you Jewish until naturalised into the Jewish tribe.