I often ask people who comment on my stories "What is a Jew?" Few answer. Not that I blame them. It's complicated. You wrote thousands of words and though I feel I understand it a thousand times better after reading your fascinating essay--I'm no closer to understanding than before.
I'd add on other attribute. Asking the question, "What does it mean for me to be Jewish". Other religions splinter apart, with both claiming perfection, while I feel (just opinion) that Jews are always up for a discussion. I've been arguing with a Jewish (Israeli) friend for five years and we disagree on just about everything and yet, every day, we go at it again, trying to convince the other that this or that is good or bad for Jews (leaving the definition aside).
Anyway, I REALLY enjoyed your essay. I will probably link to it whenever the question comes up!