After the passing of Rabbi Yehudah Tzvi of Setrin, the elder chassidim refused to accept the leadership of his son, Rabbi Avraham, saying, “The face of Moshe was like the sun, while his student, Yehoshua, was only like the moon.”
The young Rabbi Avraham responded: “Concerning Avraham Avinu, the verse (Bereishis, 12:5) states that he made converts. But where are all those converts today? Apparently, after Avraham passed away, they stated, ‘We no longer have a Rebbe,’’ and therefore returned to their wayward ways.”
(Otzar Agados HaChassidim, Vol. 10, Pg. 46)