The doctrines of Chasidus, in general, and of Chabad-Chasidus in particular, are nothing but an explanation of, and clear indication to, the meaning of the verse, All the earth is full of His Glory,1 based on two principles:

a) Everything is the Divine Being, and b) the Divine Being is everything.

The principles of Chasidus teaches that: There is no space devoid of Him and No thought can conceive Him. Chabad Chasidus extends these principles by explaining at great length and expounding with the aid of abundant empirical examples, what is meant by there is no space devoid of Him. Furthermore, it teaches that though no thought can conceive Him, nevertheless, it is the duty of man to seek enlightenment in the wisdom of G‑d, and to understand and conceive it to the best of his intelligence, as it is written:2

You shall know this day and reflect in your heart that the Lord is G‑d, in the heavens above and upon the earth below; there is no other.

In the course of ten years since the first disciples left the study hall of the Alter Rebbe, and settled in various districts all over the country, each man in his vicinity had set up a lighthouse, spreading the light of Chabad Chasidus, teaching the Jewish people to serve G‑d in a spirit of intelligent recognition and conception.

Those Chasidim taught as well as practiced the word of according to the teachings of Chasidus, which was their guide in daily life.