The inner meaning and the secrets of Torah are such that it is not possible for a Jew to ignore them; he must be involved with them to the extent that he is capable. He must be involved with Torah and mitzvot with proper intention in order to acquire the aspect of Ruaḥ at the appropriate level for him. He must also be involved in the secrets of Torah at the appropriate level so that he can acquire the aspect of Neshama at the proper level. The same [is true] regarding [study of] the reasons for the commandments. For even the smallest light in sacred reality cannot be perfected without these areas of study.
Every Jew Must Engage with Inner Torah
Baal HaSulam's Introduction to Zohar 56:2