The Upanishads are the only scriptures in the world which declare:-

The Upanishads are the only scriptures in the world which declare:-

It is impossible to find and realize the truth via religion and scriptural study. Even Upanishads conform this. 

Katha Upanishad:-

  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 Ataman 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 Upanishad says:  the human goal is to acquire Self-Knowledge and they indicate the personal gods, scriptures, worship and rituals are not the means to Self –Knowledge, then why anyone should indulge in it. The religion, concept of individualized god and scriptures are greatest obstacle to realize non-dual truth or self-realization, because they are based on false self.  The seeker of truth has to search the ultimate truth without losing himself in the labyrinths of philosophy, through deeper, inquiry, analysis and reasoning and assimilate and realize it.

That is why Sri Sankara, indicated  in Bhaja Govindam says: - [Jnana Viheena Sarva Mathena Bajathi na Muktim janma Shatena] - one without knowledge does not obtain liberation even in a hundred births, no matter which religious faith he follows.

Then it is no use going roundabout way, trace the Brahman which is the formless substance and witness of the universe, which is in the form of mind.