" And how shall we be able to tell whether he is a true zaddik?” The Baal Shem replied. “Ask him to advise you what to do to keep unholy thoughts from disturbing you in your prayers and studies. If he gives you advice, then you will know that he belongs to those who are of no account. For this is the service of men in the world to the very hour of their death; to struggle time after time with the extraneous, and time after time to uplift and fit it into the nature of the Divine Name. "

― Martin Buber , Tales of the Hasidim, Vols 1-2