Answer: He does it through suffering because I suffer when I do not know but wish I could know, attain, sense, and see! The Kli (vessel), which is suffering, is the basis for attainment. However, suffering can be suffering of love and aspiration for the desirable, which makes it sweeter than the actual attainment.
When you aspire to something you desire, the vessel in which you receive the attainment is unlimited. You don’t know what it is and so you exist in a search, in flight. Once you attain something, it turns out to be very limited. This is because you placed a limitation upon it. In the end we reach the complete correction where the Kli is not limited by anything.
Question: Is the word “suffering” the key to both our world and the spiritual?
Answer: Yes, but it depends upon what kind of suffering: necessary for the attainment of pleasure, the fulfillment of reality, or unanswered suffering.
From the Kabbalah Lesson in Russian 8/12/18