Sage Sankara does not believe in the book. Sage Sankara denies the authority of any book over any other book.+

Sage Sankara does not believe in the book. Sage Sankara denies the authority of any book over any other book. 

Sage Sankara denies emphatically any one book containing all the truths about God, Soul, and the ultimate reality.

Those of you who have studied Upanishads remember that again and again, “Not by studying scriptures  can we realize the Self”

Second, it finds veneration for some particular person still more difficult to uphold. If you are seeking the truth then you should not cling to any particular scripture or  Guru or Godmen or their teachings. Not one man or woman has become object worship. 

No man has to worship as God because he is part of the Maya. by worshipping holy books, or holy man Self-realization or   God-realization is an impossibility.

Sage Sankara strongly advocated the study of Upanishads, and at the same time cautioned that the study of Upanishads alone would not lead to moksha. In matters 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; that 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).

That is why Sag Sankara says: ~ VC 56- Neither by Yoga, nor by Sankhya, nor by good work, nor by learning, but by the realization of one's identity with Brahman is Liberation possible, and by no other means.

There has never been a single scripture, which has the whole wisdom in it.

Scriptures are being added from time to time. This process will go on. There is the final authority among the scriptures. One contradicts the other: duality reigns supreme.

The Upanishads are self-contradictory. Every pundit even gives conflicting interpretations of them. The final authority, therefore, is using one’s own reason. One should apply his reason to them.

The scriptures are for ignorant masses, who wholly accept the material world as it presents itself. Gnana is for those who have begun to realize that things are not what they seem.

The Scriptures are of value only when dealing with persons who are incapable of understanding truth. They have no value as authority for those who use reason.

I quote only verified citations from the scriptures. I need no scriptures but I quote them to help the seekers to realize that religion, scriptures, and  Gods based on blind faith or blind belief is nothing to do with the ultimate truth or Brahman or God in truth.

The Upanishads are the only scriptures in the world that declare:~

It is impossible to find and realize the truth via religion and scriptural study.

That is why Sage Sankara says in Vivekachudamani:~

58. Loud speech consisting of a shower of words, the skill in expounding the Scriptures, and likewise erudition - these merely bring on a little personal enjoyment to the scholar but are no good for Liberation.

59. The study of the Scriptures is useless so long as the highest Truth is unknown, and it is equally useless when the highest Truth has already been known.

60. The Scriptures consisting of many words are a dense forest that merely causes the mind to ramble. Hence men of wisdom should earnestly set about knowing the true nature of the Self.

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?

62. A disease does not leave off if one simply utters the name of the medicine, without taking it; (similarly) without direct realization one cannot be liberated by the mere utterance of the word Brahman.

63. Without causing the objective universe to vanish and without knowing the truth of the Self, how is one to achieve Liberation by the mere utterance of the word Brahman? — It would result merely in an effort of speech.

64. Without killing one’s enemies, and possessing oneself of the splendor of the entire surrounding region, one cannot claim to be an emperor by merely saying, ‘I am an emperor’.

65. As a treasure hidden underground requires (for its extraction) competent instruction, excavation, the removal of stones and other such things lying above it, and (finally) grasping, but never comes out by being (merely) called out by name, so the transparent Truth of the self, which is hidden by Maya and its effects, is to be attained through the instructions of a knower of Brahman, followed by reflection, meditation and so forth, but not through perverted arguments.

Religion is based on the body (form) as the Self since it is based on birth. Spirituality is based on the soul (formless). Thus,  there is a need to bifurcate religion from spirituality.

Religion views and judges from the standpoint of the physical self/ego, whereas in the path of wisdom,   everything is viewed, judged, and concluded,  on the base of the Soul, the  Self.  

Whatever is based on the physical entity (ego or you)  is not spirituality,  because the soul, the  Self has no form, so it has no religion.  Therefore, the seeker of truth has to rectify the reasoning base, from form to formless, to understand and assimilate the Self-Knowledge or Brahma Gnana or Atma Gnana.   :~ Santthosh Kumaar