BH
Summary of Rabbi Shmuli's comments at the Fromovitz Chabad Center's Yud Tes Kislev celebration:
The essence of Chabad can be understood on a simple, a deeper and a deepest level.
Simply: Love G-d, love Torah, love your fellow Jews. And they are all interrelated. Love G-d by loving His Torah and His Jews. Love the Torah by loving G-d and sharing her with fellow Jews. Love your fellow Jews by connecting them to the Torah and to G-d's love for them.
Deeper: In Kabbalistic terminology, Chabad is about creating unifications. To unite the creation with the creator. Until all of creation is fully brought back into G-d's complete oneness, G-d feels incomplete, unsatisfied. Thus it becomes imperative to encourage fellow Jews and even every human being to serve G-d.
Deepest: Rabbis of old said, "I set G-d before me (lit. across from me) constantly" is a recipe for behavioral success, as one is constantly conscious of G-d's expectations and watchful eye. But G-d remains at a distance, so to speak.
The Baal Shem Tov teaches it differently. "Shivisi - I have achieved equilibrium, calm, steadiness in my whole life," because, "Hashem linegdi samid - G-d is before me (lit. across from me) always." I am constantly reminded that G-d is in control and that everything that happens to me is exclusively from Him. Yet, G-d remains "across from me".
Then the Alter Rebbe brought G-d from across the way, into the heart of every person. You have two lives, says the Rebbe, the body's life and the divine life of the soul - a veritable piece of G-d. Another way to say this; the very life you live is G-d.
The result; there is always a piece of you that only wants what G-d wants and loves what G-d wants. 
