Baal HaSulam “The Teaching of the Kabbalah and Its Essence”: The names, appellations, and Gematrias belong entirely to the wisdom of Kabbalah. The reason they are found in the other languages, too, is that all the languages are included in the wisdom of Kabbalah. This is so because these are all particular cases that the other languages must be assisted with.
The language of Kabbalah is the main language of revealing the Creator. In principle, all four languages of attainment are intended for this. However, the other three languages (Tanakh , Halachah and Haggadah) are “accompanying,” they are included in the language of Kabbalah but exist by themselves to add different touches by their presentation.
Thus there is one language for the revelation of the Creator, containing four facets; the most important one is the language of Kabbalah. It includes everything, it is higher than the rest, and it is included in everything. All the symbols, all the forms of presentation, everything we read in the books of Kabbalists are written by the language that they had created to explain the revelation of the Creator to the human being. Everything is intended only for this.
Therefore, as Baal HaSulam writes in “The Introduction to The Study of the Ten Sefirot,” the one who opens books written by Kabbalists of different generations, i.e., by people who are in spiritual attainment, and use it not for this purpose, he brings adverse consequences upon himself. Instead of praising the approaching dawn like a rooster, he becomes like a bat, living only in the darkness and strongly resisting the light of day, which is already approaching for us.
From the 4th part of the Daily Kabbalah Lesson 11/21/13, Writings of Baal HaSulam