Answer: The purpose of creation is to achieve a full revelation of the Creator, and such revelation of the Creator is achieved to the extent that our properties are similar to His properties. Therefore, an ascent refers to equalizing with Him in His properties or ascending to Him to a greater extent than before. A descent refers to our distancing from Him.
The Creator is the property of absolute bestowal and love. If we get closer to Him, that is, if we acquire this property, then we ascend to Him as if climbing a mountain. However, if additional egoism arises within us, which we have not yet covered with bestowal and love, then under its influence, we descend down the mountain.
Question: It is like inhaling and exhaling. Before I rise, I must always fall. It turns out that a new layer of egoism is revealed. Is this what we call a descent?
Answer: Yes. Although, generally speaking, this is not a descent. In Kabbalah, this is called “rising within the left line” because you cannot ascend without a new layer of egoism.
From KabTV’s “Fundamentals of Kabbalah,” 3/27/19