Original sentence: Rabbi Yosef Yitzchok Schneersohn, 6th Lubavitcher Rebbe, and his successor, Rabbi M.Schneersohn, had a core of dedicated Chassidim who maintained Yiddishkeit throughout the Soviet Union, making all the difference to the new ba'alei teshuva.These Chassidim maintained underground yeshivos, mikvaos, and shechita and provided circumcision, all with incredible self-sacrifice, which entailed imprisonment, exile, and even death
Edited sentence: The fact that Rabbi Yosef Yitzchok Schneersohn, 6th Lubavitcher Rebbe, had a core of dedicated Chassidim who maintained underground yeshivos, mikvaos, and shechita and provided circumcision