I think you're right and this is something I've struggled with. I have a Jewish mother and had a bar mitzvah but I don't believe in God and think all religion is pretty stupid. Nevertheless, I have decided to officially convert (be baptised) even though I don't believe in that religion any more than I do in Judaism. I just don't want to have to deal with this debate. I don't want to be "Jewish" anymore. Some of you will say I never was. I have no interest in Israel; I am an American. I am not a Zionist; even my mother's grandfather and great-grandfather were anti-Zionist atheist socialists. So what's left? Liking some food or my knowledge of Yiddish? In New York, my African-American Christian friends do that, too. So I resign. It's unfortunate that just saying I'm not Jewish anymore didn't work; I had to accept allegiance to a religion I don't believe in just to stop being a Jew. (And of course, in the Nazi sense, I am still a Jew.) But now I feel a lot freer. So in a way I agree you have to pick one religion. Unfortunately, there's no way of stopping being Jewish unless you proactively become a Christian, Muslim, Hindu or whatever.