Sage Sankara cautioned that study of Upanishad alone would not lead to moksha.+

Sages of truth restrained themselves parting the Self-knowledge or Brahma Gnana or Atma Gnana to the mass and only a selected few.

Self-knowledge or Brahma Gnana or Atma Gnana was hidden from the people who were not qualified and receptive to it. Self-knowledge or Brahma Gnana or Atma Gnana was not written down but was imparted orally to the chosen few. Thus, religion was given to the ignorant populace and the knowledge of the Spirit, God is given only a selected few.

Bhagavad Gita says: ~ Among thousands of men, scarcely one strives for perfection; and of those who strive and succeed, scarcely one knows the ‘Self’ in truth.

The path of wisdom attracts only those who are in search of truth and they appreciate it greatly.   The ignorant are not spiritually matured they receive Self-knowledge or Brahma Gnana or Atma Gnana.  The ignorant indulge in argument and provocation and personal attack, which hinders their own realization of the ultimate truth or Brahman. 

Sage Sankara cautioned that the study of Upanishad alone would not lead to moksha. In matters of such as spiritual attainment, one’s own realization was the sole authority and it cannot be disputed

Sage Sankara also said the study of Upanishad was neither indispensable nor a necessary prerequisite for attaining the human goal, the moksha.

Sage Sankara pointed out; even those who were outside the Upanishad fold were as eligible to moksha as those within the fold were. He declared that all beings are Brahman, and, therefore, the question of discrimination did not arise. All that one was required to do was to get rid of ignorance (Avidya or duality).

The seeker's aim is the search for the Ultimate Truth or Brahman.  The search to find the non-dualistic or Advaitic truth that in actuality never was lost, only hidden.

Upanishad aspiration is best expressed in the following sutra:~

OM Asato ma sad gaMaya , tamaso ma jyotir gaMaya , mrityor ma aamritaam gaMaya . Shanti, Shanti, Shanti

"OM Lead me from ignorance to truth, from darkness to light, from death to immortality. Peace, Peace, Peace" (Brhadaranyaka Upanishad (1/3/28).

Upanishads are based on the insights of the sages and seers, serve primarily as a guidebook. One has to accept the Ultimate reality as Brahman or God.

The Sruti itself’ says:~  "This Atma is NOT to be attained by a study of the Vedas.  (Katha Upanishad I, 2, 23.)     

Sage Sankara says: ~

Aparoksh Anubhuti: ~

A. A 5~ Atman (the seer) in itself is alone permanent, the seen is opposed to it (ie., transient) – such a settled conviction is truly known as discrimination.

A.A 19. Atman is all consciousness and holy, the body is all flesh and impure; and yet, etc.,

A.A 45. There exists no other material cause of this phenomenal universe except Brahman. Hence, this whole universe is but Brahman and nothing else.

A.A 46. From such declaration (of the Shruti) as “All this is Atman”, it follows that the idea of the pervaded and the pervading is illusory. This supreme truth is being realized, where is the room for any distinction between the cause and the effect?

A.A 47. Certainly, the Shruti has directly denied manifoldness in Brahman. The non-dual cause being an established fact, how could the phenomenal universe be different from It?

A.A 48. Moreover, the Shruti has condemned (the belief in variety) in the words, “The person who”, being deceived by Maya, “sees variety in this (Brahman), goes from death to death”.

A.A 49. Since all beings are born of Brahman, the supreme Atman, they must be understood to be verily Brahman.

A.A 50. The Shruti has clearly declared that Brahman alone is the substratum of all varieties of names, forms, and actions.

A.A 51. Just as a thing made of gold ever has the nature of gold, so also a being born of Brahman has always the nature of Brahman.

A.A 53. When duality appears through ignorance, one sees another; but when everything becomes identified with the Atman, one does not perceive another even in the least.

A.A 54. In that state when one realizes all as identified with the Atman, there arises neither delusion nor sorrow, in consequence of the absence of duality.

A.A 55. The Shruti in the form of the Brihadaranyaka has declared that this Atman, which is the Self of all, is verily Brahman.

A.A 56. This world, though an object of our daily experience and serving all practical purposes, is, like the dream world, of the nature of non-existence, since it is contradicted the next moment.

A.A 57. The dream (experience) is unreal in waking, whereas the waking (experience) is absent in the dream. Both, however, are non-existent in deep sleep which, again, is not experienced in either.

A.A 58. Thus, all the three states are unreal since they are the creation of the three Gunas; but their witness (the reality behind them) is, beyond all Gunas, eternal, one, and is Consciousness itself.

A.A 59. Just as (after the illusion has gone) one is no more deluded to see a jar in earth or silver in the nacre, so does one no more see Jiva in Brahman when the latter is realized (as one’s own Self).

A.A 68. Atman, though ever pure (to a wise man), always appears to be impure (to an ignorant one), just as a rope always appears in two different ways to a knowing person and an ignorant one.

A.A. 87. Thus, through ignorance arises in Atman the delusion of the body, which, again, through Self-realization, disappears in the supreme Atman.

A.A. 88. When the whole universe, movable and immovable, is known to be Atman, and thus the existence of everything else is negated, where is then any room to say that the body is Atman?

A.A 96. The real nature of the rope being known, the appearance of the snake no longer persists; so the substratum being known, the phenomenal world disappears completely.

A.A 98. “And all the actions of a man perish when he realizes that (Atman) which is both the higher and the lower”. Here the clear use of the plural by the Shruti is to negate Prarabdha as well.

A.A 99. If the ignorant still arbitrarily maintain this, they will not only involve themselves in two absurdities but will also run the risk of forgoing the Vedantic conclusion. So one should accept those Shrutis alone from which proceeds true knowledge.

Even as particles of sand floating in water settle down when the water is absolutely steady, A person who has gained the  Self –knowledge or Brahma Gnana or Atma Gnana of truth rests in the consciousness.

Sage Sankara: ~ VC In the dream state, even though there is no contact with the outside world, the Soul alone projects the entire dream universe of enjoyer, enjoyment, etc. Similarly, the waking state is no different. All this world of pluralistic phenomena is illusory projection.

The Upanishad has spoken of the sleep state at length.  This has several purposes. 

   1. To reiterate that the objective world does not have a permanent reality

   2. To demonstrate that the subject alone remains as the non-dual reality in the sleep state and therefore in all the states.

   3. To prove that the sleep state, being non-dual, gives the greatest bliss to the subject consciousness.

   4. To prove to the subject-enquirer that bliss is obtained not from objects but on the contrary, in the absence of objects.

   5. To prove that duality is samsara, misery and non-duality are liberations, bliss.

   6. To give to the Sadhaka a? Preview? a foretaste,  of the liberated state.

 Brihadaranyaka Upanishad 4.3.22~ alludes to this experience: ~ (In this state a father is no father, a mother no mother, Gods,  no Gods, the Vedas, no Vedas.  In this state, a thief is no thief, the killer of a noble Brahmana no killer, a monk no monk, a hermit no hermit. This form of his is untouched by good work and untouched by evil work, for he is then beyond all the woes of his intellect.

Sage Sankara: ~ 'Like a servant who carries a lamp in front of you to find your way, and you have found it, so becomes the Veda to that person. What is the Veda? ~ utterances of those who have known the Truth. Here is one who has known the Truth; why should he or she depend upon the Veda further? Actual realization takes you beyond books. At a certain stage, books become a botheration. The Upanishad itself says that the 'words are only so much of distraction for such minds'

Upanishad itself says: ~ vacho viglapanam hi tat~ words are only so much of distraction for such minds'.

Someone posing as a Gnani is not a Gnani. If someone poses himself as a direct disciple of some Guru is not a Gnani. Those who pose themselves as Gnanis are not Gnanis. A Gnani never poses himself as a Guru, a swami, a sadhu or a yogi, or some Guru’s disciple. : ~ Santthosh Kumaar