A complaint was brought to the Alter Rebbe against his chassidim: "They prolong their
davening and are careful with their performance of the
mitzvos, but their efforts are superficial and they do not truly uphold that level of piety!"
The Alter Rebbe replied: "Is it really so; is it really so? If it is, then they are deserving of the verdict of the mishnah (end of Peah 8: 9): 'One who does not limp and is not blind, yet makes out as if he is, will not die until he becomes one of them!!' Since they act like chassidim, and act with love and fear of G-d through meditation and prolonged davening, then surely they will not leave this world until it is truly so!"
Toras Menachem 5711, Yud-Beis Tammuz, p. 200