Why is Hassidut taught at religious Zionist Yeshivot if it is forbidden to teach Kabbalah to the masses? The usual argument is that there is a halachic leniency to teach it in order to combat assimilation, but that does not apply if the people are already religious.
Today, the wavering between being religious and non-religious is very common. With the threat of assimilation and the stronger-than-ever attraction to forbidden practices, rabbis correctly teach the practicing Jew the appealing, beauty and depth of mitzvot as found in chassidut (based upon Kabbala) with the same zeal as they teach them to the “not-yet” religious. In other words, today, there is very little "insurance" that people will stay religious unless they learn the "higher" and deeper ideology. Rav Kook explains that already 1,800 years ago, the mishna (Sotah 9, 15) mentioned the inevitable necessity (!) of a universal rebellion against religion, davka as we approach redemption, in order to beneficially "force" the rabbis to rediscover (!) those deeper topics which were being neglected in the classic yeshiva world. Shallow religions cannot compete in a complex world which demands deep and meaningful ideology and subsequently, identification. Rabbi Ari Shvat