Most of us here have a practical background, having spent many years in the practice of a meditative method or art (e.g., qigong, yoga, taijiquan, etc). It is true that having a practice is essential for growth and learning. And yet, many seem to gloss over the role of knowledge.
There are two kinds of knowledge -- one that is taught to us by another (such as a teacher, friend or some other medium -- book, etc). Let us call this "external knowledge" or "indirect knowledge".
The other is the knowledge that is directly known -- usually as a result of a regular and diligent practice of the method of our choice. Let us call this "internal knowledge" or "direct knowledge".
I've seen many practitioners of spiritual arts scoff at the external knowledge because it is considered somehow inferior to the "directly" known, internal knowledge that is supposed to be the fruit of our (glorious/valiant/heroic/add your own adjective here) efforts. And yet, we would not have embarked upon the path of our choice if we didn't have an external source of knowledge to guide us throughout our journey.
It is quite possible that some people, due to their karmic influence are easily able to enter into deep meditative states. But that may not result in full awakening, without proper initiation into the external knowledge. The reason being, when the deep meditative states (samādhi) are entered, there is no mind involved (or minimal mind is involved). While repeated immersion into these deep states can result in thinning of the modifications of the mind, the mind still remains functional once one exits from such states.
In the vedantic tradition, the entry into samadhi is called "mano laya" (or pausing of the mind). This is considered an intermediate stage of spiritual evolution. Once the practitioner exits from the samadhi, the mind resumes its functioning (perhaps with not as much vim and vigor as it did prior, but it generally tends to gather steam and pick up from where it left off eventually).
The only way to cause what in vedanta is called "mano nāsha" (mind cessation) is to deliberately and methodically work with the external knowledge (as taught by the teachers and texts) and go through a process of intellectual assimilation. The mind has four components, namely the ego, the thought field, the storehouse of memories and impression and the intellect. For knowledge to be integrated, it has to be worked on with the cooperation of the mind (ego-thought field-storehouse-intellect).
Key among them is the intellect. Whatever the intellect identifies with, the ego will do its level best to protect/maintain that. If the intellect identifies with the body, the ego will strive to maintain that identification. If the intellect identifies with the mind, ego will strive to maintain that identification. Therefore, the intellect needs to come onboard with the process of spiritual development. Once the intellect is onboard, all the other components of the mind will follow its lead. So with the study and contemplation on the external knowledge using the intellect, the intellect needs to be convinced of its 'place' in the grand scheme of things.
When the intellect understands completely that it is merely a function of the mind, and that the mind is nothing but a process arising in awareness, the intellect will gradually relinquish its need to identify with anything. It might initially start by giving up identification with the body and the mind.
Typically the intellect latches onto the idea of being "The Non-dual Self/Awareness". And it is a far better proposition that being identified with the body/mind. Then the seeker wants to constantly abide in this "non-dual awareness". Of course, life usually has other plans, so the feeling of non-duality, and the feeling of duality keep coming and going, oscillating between the two phases at regular intervals. This leads to great frustration in the intellect of the practitioner. And then one day the realization occurs, that what we truly are, is aware of both the duality and non-duality that seems to arise in the mind. And on that day, the intellect gives up completely, and the ego disappears, as it has nothing to defend anymore. This results in a fully non-grasping mind, essentially a mind that has ceased to operate as it used to before spiritual practice started. And therein is the direct knowledge or internal knowledge, which is nothing but that which is aware of both the apparent duality and non-duality.