"Kabbalah permeates every aspect of Judaism"
Jewish mysticism never really became a separate domain of spiritual life outside the religious tradition.
This may be due to the fact that the initial revelation at Mount Sinai was holy in such a way that it could never be shaken off.
The Torah scriptures, at all levels of their composition, from the Bible to the Talmud and the latest commentaries of the sages, succeeded in retaining and elaborating this experience so profoundly that there was not much room for an emotional mysticism, either private or cultic, to develop on its own, outside of the established religious form.
At a certain stage in Jewish history (from about the seventeenth century), the religious authorities believed that there was a significant danger in that direction.
And in Europe at least, Kabbalah, the chief repository of the mystical aspect of the tradition, was taken firmly in hand.
Only mature students were permitted to study it, and carefully preserved texts were left to gather dust and sink into oblivion.
In later years (mostly in the nineteenth century) there was another, newer element that helped to suppress the mystical lore.
Within the strong rationalistic tendency of the age, many influential people (such as the authors of the most important books of Jewish history) were fiercely antagonistic to any mystical approach and tried to disparage it and even deny its existence in the past.
The apologetic mood of the time demanded hiding these shameful parts of Judaism and trying to forget them entirely.
The result has been a general misunderstanding of the role of the Kabbalah, and of the mystical experience altogether, in Judaism.
The truth is that the Kabbalah permeates every aspect of Judaism, and the "esoteric wisdom" has been a basic ingredient of scripture, ritual, and prayer.
Even many popular expressions, in Hebrew but also in the colloquial Yiddish, have their source in the Kabbalah.
From "The Mysticism in the Jewish Tradition" from On Being Free by Rabbi Adin Steinsaltz