Those who accept the Covenant Of Moses are Jews by inheritance. It's a spiritual thing that shouldn't be determined by scientific means. Those who link their destinies with those of the Jewish People are Jews as well. We don't get to pick our relatives. They just exist. Both the good and the bad. If Madonna or Whitney Houston want to call themselves Jews, who am I to judge? As for two or more covenants existing simultaneously, make your own judgements. Remember, a drowning man might go through every name in the book in an attempt to stay alive. Only one idea may unlock the door. And then there is the question of what is conciousness and whether any of that energy still holds together afterwards? So there's always time to make the right choice, in my opinion. Anyway, as I remember it, someone once said after 9/11, we are all Jews now.
Italian synagogue damaged in severe storm (JTA)
from the article: A Jew is not a number