The wisdom of Kabbalah uses only those terms and names which are real and reflect reality. This is an immutable law of all Kabbalists: “That which hasn’t been attained is impossible to name and define.” Until an object is revealed completely, as if you’re holding it in your hands, Kabbalists don’t call it attainment but something else like understanding, knowledge, and so on.
In this manner, we attain a phenomenon to its very foundation, from the beginning of creation until the end, in every detail. And as much as we attain it inside our vessels of perception, to that extent we ourselves become enriched and complex in equal measure. After all, all the worlds are inside us and the entire picture appears within. I don’t study external phenomena but whatever occurs inside of me, and in the process, I understand myself more and more and realize to a greater extent that there is nothing outside of me. If before I saw the world as being outside, it was only due to a distorted perception, while in reality, it was a projection reflected in my brain.
Ultimately, the spiritual attainment leaves no doubt, just like I don’t doubt basic, elementary things, such as how many fingers I have on my hand. And this is why it is written in different places that Kabbalah doesn’t require proof, since it cannot offer any proof to a person who is not in attainment. Words taken on faith won’t help here; a person needs to ascend to a level of attainment, to feel inside him or herself the screens, the Lights, and the vessels. Then he will see reality—see it firsthand with his inner sight.
Then our world will suddenly appear to be inside as well. Indeed, as the desires are corrected, a person feels the facets and manifestations of the world inside him. When we work in a group, trying to bring the friends closer in unification, bonding, and Arvut (mutual guarantee) in order to become as one man with one heart, then through that, we prepare ourselves for that very same perception, which depends wholly on a person himself. And this is why spiritual attainment has no boundaries. All that we see outside transitions inward, becoming a part of us.
From the 3rd part of the Daily Kabbalah Lesson 6/8/12, “The Essence of the Wisdom of Kabbalah”