Throughout generations, those who were engaged in the internal part of the Torah were going through self-transformation; they worked for the sake of the Creator and attained spirituality. It’s impossible to attain Him alone except for special cases that occur to those who are granted revelation from Above for a special purpose. That’s why Kabbalists had to always stay connected with their friends, as one man with one heart, in mutual guarantee.
It was always done “in humility.” Even though each worked in unity for the sake of their friends, they never demonstrated this outwardly. Most of the time, it was the other way around; they ostentatiously displayed disregard for each other and towards their internal work as it was among the Kabbalists of Kotzk. They acted this way to conceal the true aspiration of their hearts, and thus enable them to apply efforts and advance.
There were other groups who studied, prayed, and discussed things together, for example, Ramchal’s students. But still, they were careful in disclosing their hearts to each other to prevent others, even their friends, from seizing their internal desires of the heart. After all, they were burning with such powerful intention to the goal that nobody had the strength to express it outwardly in words and everybody was entirely focused on their internal sensations.
Only after many years, closer to our time, precisely since the Ari and then Baal Shem Tov and the Magid from Mezeritch, when the movement for the use of Kabbalah in large groups (Hasidism) emerged, they started to gradually speak more about the internal work.
So we came to our time when we can talk about it more openly, not only among us, but even explaining the principles of spiritual work to the general public to wake up the hearts of many for spiritual work.
At the same time, we have to protect ourselves. Protection is made through intentions: The more our hearts are tuned to the internal wave, the more we become immersed in it and won’t seek to vent our hearts’ hidden aspirations.
From the Preparation for the Daily Kabbalah Lesson 12/10/13