Answer: There is a tremendous difference, which is truly impossible to explain. It is the same as to live in Israel or some other countries, in the Temple or outside of it, or to be a great priest or a regular person.
The tiniest changes, a small ascent in the worlds, evoke tremendous transformations within our souls. The worlds of Beria, Yetzira, and Assiya are internal desires of our souls. We are always present in the three worlds of BYA and cannot disappear from them.
They serve as the “wrappers” around our souls. Just like now, I reside in this world and cannot escape anywhere from it since my body belongs to this world. I live, grow, mature, and die, while still remaining in this world. My body’s entire matter is part of the material world, whether I am alive or dead and disintegrate and return to the earth.
Similarly, a soul, regardless of the state it is in, always remains in the worlds of BYA. In the meantime, we reside only there, where we ask for correction and draw the Surrounding Light. It can pass down to us and illuminate downward, beneath the Parsa, from the world of Atzilut, although the Parsa doesn’t let the Light through. But this is the “surrounding” Light, and it illuminates from afar, awakening and calling us as if from a distance: “Come and see what I’ve got!”
Then I wake up and ascend along with the worlds of BYA above the Parsa. But I can’t rise without them since I am tightly connected with them: They are the closest “to my skin,” clothing me like a dress. I live in the world, but I am wearing “clothes”—they are the very worlds of BYA. And in them, I ascend to the world of Atzilut, which is regarded as “the ascension of the worlds.”
But as soon as I ascend to Atzilut and force the worlds of BYA to rise to it with me, I thereby receive a volume, an enormous empty vessel that I fill with the Inner Light of Atzilut. This signifies that my soul has been filled with the Light.
Desire has let the Light, the Creator, in and is experiencing Him now! Hence, the Creator and I are together, merging one with the other in the degree of our equivalence of form. This is all; there is nothing else in all of creation.
And all of a sudden, I discover where all the friends, other people, the still, vegetative, and animate nature, and this entire universe are. Everything is contained within this very desire; nothing vanished, but rather acquired a different form.
All that I used to see as rocks, plants, beasts, and humans turns out to be my desires that previously seemed material objects to me, which I could touch with my hands. But in truth, they are desires from which the universe is made. And beyond it, there is nothing else.
So it goes that a person ascending to the world of Atzilut with the worlds of BYA starts revealing the true image of reality. He as if gets to see what was hidden inside the computer, behind all those images he was shown on the screen. That’s what is called revelation!
From the 3rd part of the Daily Kabbalah Lesson 5/6/2011, “Explanation of the Article, ‘Preface to the Wisdom of Kabbalah’”