It would appear to me and surely others that
that claim is preposterous because in fact, those
that reject the Brit Olam covenant e.g Saul (Paul)
Jewish people have with the G-d of Israel (the right way)
and the 7 Noahide commandments are the ones if anything,
that are candidates for Gehinnom. If they change and
do Teshuvah, they have a significant chance at ‘real’
redemption. Rabbi Tovia offers yet another enlightening
commentary on this ‘controversial’ topic.