The Kabbalists attain a complete thing. Meaning, they are rewarded with attaining all of those degrees existing in reality, attainable to man, and then it is considered that they have attained a complete thing, and that complete thing is called, “a soul.”
Baal HaSulam, “The Meaning of Conception and Birth”
Anyone receiving the abundance from the Creator is glorified with the crowns of the Creator. And one who is rewarded with feeling, during the fact, how the Creator is glorified with him, for having found him ready to receive His abundance, he is called “a Kabbalist.”
Baal HaSulam, Letter 46
The wisdom of truth is conditioned by all the teachings, and all the teachings are conditioned by it. This is why we do not find a single genuine Kabbalist without comprehensive knowledge in all the teachings of the world, since they acquire them from the wisdom of truth itself, as they are included in it.
Baal HaSulam, “The Teaching of the Kabbalah and Its Essence”
The depths of the Divine secrets simply cannot be comprehended by scrutinizing them with the human intellect, but rather by the Kabbalah, through wondrous people, whose soul has been imbued with the Divine Light.
Rav Raiah Kook, Orot HaKodesh (Lights of Sanctity) Vol. 1, 85
The truly righteous can perceive the purpose of the next world with their minds.
Rabbi Nachman of Breslev, Collection of The Moharan, “Torah,” 18
Were it not for sages, people would not know what is the law and what are the commandments of the Creator, and there would be no difference between the spirit of man and the spirit of a beast.
The Book of Zohar (with the Sulam [Ladder] Commentary), Shemot [Exodus], Item 84
The secrets of the Torah will not be revealed to people by means of their material study, but through Divine abundance, imparted from the height of His holiness by His emissaries and angels or by Prophet Elijah.
The Writings of the Ari, The Tree of Life, Introduction of Rav Chaim Vital to Gate to Introduction
The souls of the great righteous sages encompass everything: They have all the good and evil of everything. They suffer torments for all and receive pleasure from all, as they transform the evil of all into good.
Rav Raiah Kook, Orot HaKodesh (Lights of Sanctity), 3, p 153
Understanding the meaning of the word, "spirituality," has nothing to do with philosophy. This is because how can they discuss something that they have never seen or felt? What do their rudiments stand on?
If there is any definition that can tell spiritual from corporeal, it belongs only to those who have attained a spiritual thing and felt it. These are the genuine Kabbalists; thus, it is the wisdom of Kabbalah that we need.
Baal HaSulam, “The Wisdom of Kabbalah and Philosophy”
The merit of one who has been rewarded with cleaving unto Him once more. It means that he has been rewarded with equivalence of form with the Creator by inverting the will to receive, imprinted in him through the power in Torah and Mitzvot. This was the very thing that separated him from His Essence, and turned it into a will to bestow. And all of one’s actions are only to bestow and benefit others, as he has equalized his form with the Maker. It follows that one is just like the organ that was once cut off from the body and has been reunited with the body: it knows the thoughts of the rest of the body once again, just as it did prior to the separation from the body.
The soul is like that, too: after it has acquired equivalence with Him, it knows His Thoughts once more, as it knew prior to the separation from Him due to the will-to-receive’s disparity of form. Then the verse, "know thou the God of thy father," lives in him, as then one is rewarded with complete knowledge, which is Godly knowledge. Also, one is rewarded with all the secrets of the Torah, as His Thoughts are the secrets of the Torah.
Baal HaSulam, “A Speech for the Completion of The Zohar”
Indeed, there is no generation without chosen ones who have been instilled with the spirit of holiness. Elijah the prophet was revealed to them and teaches them the secrets of this law.
The Writings of the Ari, The Tree of Life, Introduction of Rav Chaim Vital