Not a Full-Fledged Jew Without It
Torah learning
Rav Yaakov Yosef of Skver used to say that every word of the Ohr HaChaim is like a whole Torah in itself. He even said, "One cannot be a full-fledged Jew without studying this holy sefer." When a bochur's yiras Shomayim declined, he ordered him to learn the Ohr HaChaim, even on topics that were not mussar, because he said that studying its holy words is a segulah for working on the soul.
Source: Taught by the Skverer Rebbe