Answer: Baal HaSulam is a great Kabbalist who attained, generalized, and systematized the science of Kabbalah. We are engaged in Kabbalah in order to master it not in the form of science, but in the form of a method of spiritual attainment. These are two different things, although interrelated.
When a person wants to enter the spiritual world himself, then Baal HaSulam is a theoretician for him. He cannot lead a person forward. Rabash leads us forward, explaining at every step where we are, what to do, how to act, what interaction to have in a group, with ourselves, and with the Creator.
I remember well how he wrote his first article, sitting next to me on a park bench. I gave him an aluminum cigarette wrapper, and on the back of it, he wrote a small article—the first of the future three-volume book.
At first, I asked him questions and he gave written answers to them. His first articles appeared this way. Later he wrote by himself.
Without these articles, we could not advance. At each morning lesson we devote an hour and a half to two hours to the articles of Rabash, only half an hour to The Study of the Ten Sefirot (Talmud Eser Sefirot,) and half an hour to the articles of Baal HaSulam.
It is even incomprehensible how people could master the spiritual space before Rabash, how they could feel it in themselves and advance to different levels. That is what he teaches us, because in our time, souls that descend into this world need it.
Rabash is a practicum of Kabbalah and Baal HaSulam is more a theoretical Kabbalist.
In order to get closer to Rabash, one must read his articles and listen to our lessons on them. All of them are in the archive, you can use them free of charge, access is free. Go ahead, dare!
From the Kabbalah Lesson in Russian 12/23/18