ספר שיחות מוהר"ן אות - רפא

He said to someone: When one separates, Heaven forbid, from the Tzadikim — it is as if one worships idolatry. For it is brought in the holy Zohar (Tikkunei Zohar 21) that the Tzadik is the spine of the letter dalet. And when one separates from him, Heaven forbid, one thereby severs the spine of the dalet of "Echad" [One] (Devarim 6:4) — and it becomes, Heaven forbid, "Acher" [other] (Shemos 34:14) — which is "another G-d," meaning heresy.[464] For the essential faith in the unity of G-d is through the true Tzadikim who are the spine of the dalet of "Echad," as mentioned.[465] And this matter is explained in many places in the words of Rabbainu, o.b.m. — that the essential faith is bound up with drawing close to the true Tzadikim. 464. RAK: See Baal HaTurim, Devarim 6:4. 465. RAK: See Likutay Moharan 10:5.