sentences:  Rabbi Schiff, a follower of the current Grand Rabbi of Belz (Hasidic dynasty), Rabbi Yissachar Dov Rokeach, is an alumnus of the Erlau yeshiva in Jerusalem and was previously the Rabbi of the local Alexander synagogue.An essential difference between these two organizations is apparent in the Shomrei Hadas' alignment with religious Zionist doctrine, which the Machzikei Hadass rejects.Hasidic Jews comprise about forty percent of the Jews of Antwerp.