Ah, but your belief that "Judaism ceased to exist more than 2000 years ago" is a dogma of chrstianity, and we are dealing with a situation where chrstianity is untrue. If chrstianity is untrue, so is its teaching about the "supersession" (chas vechalilah!) of Judaism. To say "if I believed chrstianity were untrue I couldn't accept Judaism because I know from my untrue chrstian religion that Judaism no longer exists" is an oxymoronic statement. That's like Protestants who say "if chrstianity isn't true I'll have to go to hell because J*sus didn't really die for my sins."
BTW, I'm sure the ironic similarity of your claim that "Biblical Judaism" isn't contemporary Judaism and the Protestant claim that Catholicism isn't genuine "new testament chrstianity" has never so much as suggested itself to your mind?
Sorry, my plan is to go onward and upward, not backwards. I’m not interested in your justifications for rejecting Jesus Christ. Yes, all Christians sin. No, that is not a good enough reason for rejecting Christ.