When we read The Book of Zohar, we understand that it talks about qualities, forms, and images that we don’t perceive yet. It is precisely this sensation of not understanding that pushes us forward and makes us form the right perception.
If we read other Kabbalistic books, then we might perceive everything in a purely mechanical manner, with our mind, or in the form of material pictures. Then we will be satisfied with the perception that lowers all the concepts to the level of our world, without understanding that they are all imaginary. Alternatively, we might consider them spiritual, yet merely theoretical.
In contrast, The Book of Zohar with Baal HaSulam’s Commentary forces us to search for a new perception and to unite these two images. This results in the emergence of the true perception of reality. A person doesn’t understand how it happens, but the book works on him and he gradually acquires a new perception.