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 citation form the scriptures. I need no scriptures but I quote them to help the seekers to realize the religion, scriptures and the belief of God is nothing to do with the ultimate truth or Brahman.
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.
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 which 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 realisation 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 splendour 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.
The religion is based on the birth entity whereas the Soul, the innermost Self is birthless and deathless. Spirituality is based on the Soul (formless). Thus, there is a need to bifurcate the religion from the spirituality.