From Inner.org, the writings of Rabbi Ginsburgh (hassidic kabbalist in Israel), from his weekly mailing list (available to all, click here):
"In general there are 5 stages in the revelation of the wisdom of Kabbalah, each stage appearing (one might say, even encoded) within a particular text."
The Fifth Stage of Kabbalah: Chassidut
More than a century and a half after the Arizal’s statement that the time has come for Kabbalah to be revealed, the Ba’al Shem Tov (1698-1760) founded the Chassidic movement. As explained in length by one of the greatest Chassidic scholars, Rabbi Isaac of Homil (who was a disciple of Rabbi Shneur Zalman of Liadi, the founder of the Chabad branch of Chassidut, his son, Rabbi Dov Ber, and his grandson, the Tzemach Tzedek), the Ba’al Shem Tov’s teachings in particular and Chassidut in general are a final tier of Kabbalah. They are a unique revelation of the Divine wisdom of Kabbalah in the sense that they form a new corpus of teachings that as a whole provide a deeper insight and a more advanced conceptual scheme than ever revealed before with which to understand and internalize the teachings of the Zohar and the Arizal.
Chassidut is thus the fifth stage of the revelation of Kabbalah. But, the Ba’al Shem Tov’s Kabbalah is not different only in its breadth of explanation; it is also wider in its scope. Whereas the Arizal still imposed limitations on who is worthy to study Kabbalah, the Ba’al Shem Tov advocated a radically new approach. The Ba’al Shem Tov experienced an elevation of his soul to the dwelling place of the Mashiach in heaven, where the Mashiach revealed to him, that the redemption would occur once his [the Ba’al Shem Tov’s] wellsprings of teaching would spread forth to the most remote extremes (yafutzu ma’ayanotecha chutza). Subsequently, the Ba’al Shem Tov explained that the “most remote extremes” specifically refers to those Jews who until now could not have been considered sanctified enough to study Kabbalah.
Obviously, spreading the wellsprings of Kabbalah to these extremes means specifically addressing every single Jew, regardless of level of observance or commitment to the Torah. Not only that, but even non-Jews, who also require the wisdom of Kabbalah in order to participate in the redemption in a compassionate and merciful manner, should also be addressed and taught those parts of the wisdom that pertain to them. This implies there really are no longer any conditions placed on the study of Kabbalah. Since all souls require this wisdom to rectify themselves, there is also no difference between genders. Until the coming of the Mashiach it is our task to do all in our power to spread the wellsprings of Chassidut, the fifth level of Kabbalah.
Revealing the Concealed
It is important to mention that whenever we speak of “new teachings” we of course mean not that some new Torah has been given from God through someone, but rather that some righteous individual has merited revealing hidden parts of the Torah that were always present but remained concealed until that point in time (for reasons known only to God, in His providence to bring creation and history to the utopian state for which the world was created). Those unique souls sent from Heaven at certain critical moments in history to reveal new dimensions of the Torah will of course never contradict or nullify any of the Torah's laws or teachings that had been revealed until that point in time.
Rabbi Shneur Zalman, the found of Chabad, stated that “there will not be a second giving of the Torah,” meaning that all new teachings must always truly be founded on the Torah as it has been transmitted and developed from generation to generation. The Torah that was given by G-d at Mt. Sinai already contains all the new teachings and understandings of all the generations up to and including even the deepest revelations that will be taught by the Mashiach. In fact, the prophets clearly stated that just before the final revelations of the Torah by the Mashiach, prophecy will return to the Jewish people. The purpose of this prophecy is, again, not to reveal a “new” Torah, but rather to prepare the soul so that it can integrate the depth of the revelation of the Torah’s hidden teachings as they will be revealed by the Mashiach.
BS"D - בסיעתא דשמיא