This questioning of 'who is a Jew' came from religious quarters, as well. In any case, just because a culture is deeply religious in nature, doesn't mean that one has to be religious in order to stay a part of it, to develop it.

I agree. Indeed the majority of the Jews, in Israel and elsewhere are not religious. I was merely questioning the assertion made earlier in the discussion that having absorbed some Jewish culture qualifies one as a Jew.