90% of Jews don’t believe in G-d? That is not true.
If you mean 90% of them don’t observe their religion, that’s not true, either. I consider Conservative Jews, of whom I am one, to participate strongly in Jewish traditions - kosher, Shabbat services (usually), Hebrew School growing up, adult class for more Torah learning, holidays (Purim Party tomorrow after Megillah reading, yea!), etc., etc.
I hope you’re not one of those Orthodox Jews who considers the 85% - 90% who are not Orthodox to be not Jewish. Please tell me it’s not so.