Even Upanishad says:- This Atman cannot be attained by the study of the Vedas, or by intelligence, or by much hearing of sacred books.

Who am I?" This question was boldly taken up by the great Indian philosopher Sri Sankara (788-820 AD), who wrote commentaries on some of the spiritual treatises known as the Upanishads, which form the latter part of the Vedas, the holy scriptures of India. 

Even Upanishads says:-

  This Atman cannot be attained by the study of the Vedas, or by intelligence, or by much hearing of sacred books. It is attained by him alone whom It chooses. To such a one Atman reveals Its own form. [Katha Upanishad Ch-II -23-P-20]

Mundaka Upanishad  :-

This Atman cannot be attained through study of the Vedas, nor through intelligence, nor through much learning. He who chooses Atman—by him alone is Atman attained. It is Atman that reveals to the seeker Its true nature. [3 –page-70 Mundaka Upanishad  Upanishads by Nikilanada]

When the Upanishads say:-

It is attained by him alone whom It chooses. To such a one Atman reveals its own form.  Then what is the use of indulging through our intelligence or our accumulated knowledge, when one is not chosen by the self, which is the soul, which is in the form of consciousness. 

Even in the Buddhism: - Buddhist teaching has itself become a kind of interactive and self-evolving process, much like its idea of pratityasamutpada. However, the end goal is still Nirvana, which is an experience ultimately beyond all concepts and language, even beyond the Buddhist teachings. In the end even the attachment to the Dharma, the Buddhist teaching, must be dropped like all other attachments. The tradition compares the teaching to a raft upon which one crosses a swift river to get to the other side; once one is on the far shore; there is no longer any need to carry the raft. The far was never any river at all.

 The scriptures and theories and teaching based on the ego are not the yardstick. Using them as yardstick to understand and assimilate the truth will lead one towards pursuit of arguments. Seeker of truth has to discover on his own, the truth of his true existence by inquiring “what is mind?” and “what is substance of the mind?” and move forward.   

The ultimate truth is one without the second, the one is not in the sense half or two, but the one that remain forever One, without the second.  The consciousness is all pervading. There is no place where consciousness is not. 

Consciousness is in everyone, consciousness is in everything .consciousness is one behind many. Consciousness alone is. It means the universe is the visible form of consciousness. Formless and colourless   consciousness’s creative and impulsive imagination to know itself as omnipresent, infinite and eternal. And consciousness in turn invisible form of the universe.   

 Since people all are not aware of the fact that, they are an experience within another experience [waking/dream]. The mind is an experience, which contains everyone and everything and the universe. Since one limits the mind to the physical entity, he forgets the fact that, his body and the universe is an experience, within waking or dream experience. It is impossible to unfold the mystery of his true existence without realizing the fact that, the self is not physical but the self is consciousness.   If the self is not physical then it is erroneous to judge and conclude the truth on the base of the physical self or ego. Thus the truth has to be judges on the base of the true self, which is consciousness.  

 Until and unless one rectifies the seeking base from form to formless the truth will not be revealed. 

On the standpoint of the formless soul/consciousness :-

"There is nothing to accept,
Nothing to reject,
Nothing to hold on to,
Nothing to let go of,
Nothing to grasp,
Nothing to spurn,
Nothing to embrace,
Nothing to relinquish,
Nothing to dissolve.

This is the truth.

The deeper self-search into the nature of the mind or universe lead to self-awareness. Self-awareness leads discard the ignorance.  Discarding ignorance leads to free the self from experiencing the illusion or universe or waking as reality.  

The truth has to be un-contradictable and direct, universal appeal.  One to verify before accepting any   teaching whether it leads to ultimate end, the truth   has to be direct and universal without god, scriptures, and theories as authority o yardstick.

 Seeker has to verify the nature of the mind or universe and realize its reality is mere illusion created out of consciousness.  Concealed in the all the three states is the Atman, the consciousness which is the innermost self. The one who recognizes his identity with consciousness is freed from the ignorance. Once the ignorance vanishes through wisdom then illusion will never again be reality. Same ways as the dream reality vanishes when waking takes place the waking reality vanishes when the wisdom dawns.