Just as in Christianity Mormons and Jehovah’s Witnesses are considered quasi-Christian or pseudo-Christian, Protestants are considered Christians with some heretical beliefs and Roman Catholics the hallmark of Christian orthodoxy, where would you classify the ancient and now extinct group called the Sadducees? Would they be what Mormons are to Christianity, would they be considered Jews with some heretical beliefs like denial of the resurrection, or Jews such as yourself who are the hallmark of Jewish orthodoxy? Shalom and love from the God of Abraham, Isaac, and Jacob.
As opposed to Christianity, Judaism is not only a religion or belief, but it’s also our inborn nationality (open to converts, as well). Accordingly, if one is born to a Jewish mother, he is 100% Jewish, even if he has mistaken beliefs (like the Sadducees) and even if he doesn’t believe at all in God and never fulfilled even one of the commandments! A member of Israel is a member of Israel.