Street Farbrengen Episode 68 - Rebbe: Doctrine or Challenge?

What is the relevance of Yud Tes Kislev in this  generation? Reuven has the nerve to suggest “ don’t go to a Yud Tes Kislev Farbrengen because  you feel should.” And, if you ask who the heck am I to make such a statement… just a  slob farbrenging…..The Rebbe writes: On this day, that light is called forth, in a general way, for the entire year. It is our duty, on this day, to awaken our hearts with an innermost, elemental desire and will, in the very core of our heart, that G‑d illuminate our souls with the light of His Inner Torah.“IIluminating our souls'" depends on the difference between a challenge, and  a doctrine. Is Rebbe and his Chassidus  a challenge or a doctrine?