Talk as much philosophy as you like, worship as many gods as you please, observe ceremonies, but liberation will never come, without realizing the Oneness.

Sage Sankara said:~ Talk as much philosophy as you like, worship as many gods as you please, observe ceremonies, and sing devotional hymns, but liberation will never come, even after a hundred aeons, without realizing the Oneness.

When the Self is not the form,  then the question of whom does not arise.  A deeper self-search reveals the fact that the ‘I’ itself is an illusion.  If the ‘I’ is an illusion,  then it is no use of inquiring ‘Who Am I? . Till one holds the ‘I’ as the Self,  is caught up in the prison of duality.  

Sage Sankara:~  VC-63- "Without knowing and examining the external world, one can’t know the Truth, as the idea that the external world exists, won't go. It can go only by an inquiry into the nature of the external world.

Deeper self-search reveals the fact that by Who Am I?- inquiry, wisdom will not dawn. Who Am I?  inquiry is only for beginners and it is inadequate and useless in the later stages.

That is why Sage Sankara:~  VC-61-For one who has been bitten by the serpent of Ignorance, the only remedy is the knowledge of Brahman. Of what avail are the Vedas and (other) Scriptures, Mantras (sacred formulae), and medicines to such a one?

VC- v6~ Let erudite scholars quote all the scripture, let Gods be invoked through sacrifices, let elaborate rituals be performed, let personal gods be propitiated---yet, without the realization of one‘s identity With the Self, there shall be no liberation for the individual, not even in the lifetimes of a hundred Brahmas put together.

Sage Sankara goes on to say:~ A sickness of not cured by saying the word “medicine.” You must take the medicine. Liberation does not come by merely saying the word “Brahman.” Brahman must be realized. Until you allow this apparent universe to dissolve from your consciousness until you have realized Brahman, how can you find liberation just by saying the word Brahman? The result is merely noise. Until a man has destroyed his enemies and taken possession of the splendor and wealth of the kingdom, he cannot become a king by simply saying “I am a king.” 

A buried treasure is not uncovered by merely uttering the words: “Come forth.” You must follow the right directions, dig, remove the stones and earth from above it, and then make it your own. In the same way, the pure truth of the Atman, which is buried under Maya and the effects of Maya, can be reached by meditation, contemplation, and other spiritual disciplines but never by subtle arguments.

Avadhuta Gita:~ ~ The soul, the innermost self, devoid of life and lifelessness - shines forever. Devoid of seed and seedlessness - of liberation and bondage, it shines forever. Soul, the innermost self is the nectar of knowledge, homogeneous existence, like the sky. (3.31.34)

The soul, the innermost self, shines forever, devoid of birth - mundane existence and death. The Soul, the Self is the nectar of knowledge, homogeneous existence, like the sky.

Thou hast no name and form - even to the extent of an illusion, nor any substance - differentiated or undifferentiated. Why dost thou grieve, O Thou shameless mind?  The soul, the innermost self is the nectar of knowledge, homogeneous existence, like the sky.

Why weepest thou, friend? Thou hast no misery of birth. Why weepest thou, friend? There is no change for thee. The Soul, the Self is the nectar of knowledge, homogeneous existence, like the sky.

Isa Upanishads indicate that:`The time one spends in ritualistic practices is wasted; one can spend the same time moving forward towards Self-knowledge or Brahma Gnana or Atma Gnana, which is the main goal.

Sage Sankara had tremendous intellectual power, throwing the scorching light of reason upon everything.

The effort is necessary up to the state of realization. Even then the Self should spontaneously become evident. Otherwise, happiness will not be complete. Up to that state of spontaneity there must be an effort in some form or another.

The ever-present Self needs no effort to be realized, Realization is already there. Illusion alone is to be removed. Some say the word from the mouth of the Master removes it instantaneously. Others say that meditation, etc., is necessary for the realization. But all that is religious fable propagated by orthodoxy.

People think yogic Samadhi is liberation.  They believe it because their guru has told them. When the innocent and the honest seekers blindly believe and follow the path of yoga in order to get liberation.  They propagate the same to others. They never suspect the Guru because it is irreligious to disbelieve the guru.

Neither the guru nor the disciple verified the validity of their belief if it is right. People who give lectures and write large books on religion, yoga, and theoretical philosophy are good in their subjects but what they know and master is Gnana or non-dual wisdom is the question.

Some claim that for many years they enjoyed mystic exaltation, trances, meditations, and peace but this state passes away when the waking passes away.  The waking experience itself is an illusion from the witness point of view.  

Thus, the individual experience within the waking or dream is merely an illusion because the waking or dream is merely an object to the formless subject.  

When one thinks as an individual he has experienced Non-duality then it is as good as the dream. Non-duality cannot be experienced as a person because it is prior to any experience.  

The illuminations gained by yoga or by trance states are always temporary ones

Brihad. Upanishad~ “Yoga does not yield truth or liberation."(page~32)

Brihad Upanishad~ points out that even yoga cannot give perfect concentration and that the only way to gain it is through philosophical realization. (page 133-1st para)

Manduka Upanishad: -~ that yoga can no more succeed than the ocean can be emptied with a blade of grass.

Sage  Sankara says:~Yoga is not the means of liberation. (P -132-133 of his commentary on Brihadaranyakopanishad). 

Buddha gave up his austerities of yoga as impossible and useless. (Page.70/71 "Buddhism in Translation” by Warren) . Buddha got enlightenment only after he gave up Yoga. Unless one exercises his reason--there is no chance of getting the truth.

If one experiences Non-duality as a person then this proves he had attained a yogic condition, but not Gnana. It vanished when because it is impermanent because it was not the highest insight. The Gnani, however never loses his Gnana. Dislodging a Gnani from his insight is an impossibility.

Once one has thoroughly seen the truth he simply can't fall away from it. Many are enjoying a similar sort of mystic exaltation and peace, but whether it passes away soon or endures the whole of life, it is not Gnana, because it did not come through striving to investigate the nature of the world, which confronts them, it came only through meditation on the self; that is the yogic reward for such meditation but it is only one half.

The Gnani not only gets such inner peace but also truth because he has turned outwards also and grasped the truth about the matter, which is as much consciousness as his innermost self.

The Yogi and mystics dip into their selves but they do not understand that that is only one half of the truth and that this dipping is also a mental discipline to fit their minds to understand the true nature of the world confronts them, which understanding they must next get if they are to become Gnanis.:~Santthosh Kumaar