The Advaitic wisdom is meant for those who wish to go beyond the illusory form, time, and space.+

The Sages of truth are not religious Gurus or Saints.  The religion and its mythological Gods and mythological Gods are nothing to with the ultimate truth or Brahman or God in truth.

All sect-based beliefs are dualistic and unphilosophical nothing to do with the ultimate truth or Brahman.  In spirituality, the ultimate truth is God in truth.

Lord Krishna confesses that the oldest wisdom of India (Advaitic wisdom ) has been lost: people misinterpret and falsify it today as they did then. It is not yoga but the philosophic truth. But nobody knows it. The teachers of philosophy and leaders of mysticism or religion do not want to inquire into truth and have no time for it. (Gita ~ Chap ~IV~ v.2)

In Gita Chap.IV where Lord Krishna says: ~ “This yoga has been lost for ages" the word yoga refers to Gnana yoga, not other yogas: the force of the word this is to point this out.

Lord Krishna describes some of the other yogas but devotes this chapter separately to Gnana Yoga. So one sees even in those ancient days people did not care for Advaita; they wanted religion; hence Gnana got lost. That is why Krishna calls it "the supreme secret." Krishna points out that yoga must-see "Brahman in action."

Gita Chap.IV:~ “He who achieves perfection in Yoga finds the Self in time." This means that after his yoga is finished, he begins the inquiry into ultimate truth, and in due course, this inquiry produces the realization of the universal spirit as the result.

Understanding what is God is not so easy. Religious people can only imagine God based on their beliefs.

That is why Lord Krishna says Ch ~V: ~ “Those who know the Self in truth.". The last two words (tattvataha) are usually ignored by pundits, but they make all the difference between the ordinary concept of God and the truth about God.

No duality, no differentiation. Only Atman exists.

Bhagavad Gita: ~ “brahmano hi pratisthaham” ~ Brahman (God) is considered the all-pervading consciousness which is the basis of all the animate and inanimate entities and material. (14.27)

It proves that the all-pervading Atman, which is present in the form of consciousness, is God.   Thus worshipping the form-based Gods is meant for the ignorant populace who are incapable of realizing the truth, which is hidden by the illusory form, time, and space.  

Lord Krishna Says Ch ~V: ~ Know the ‘Self’ without the form, time, and space.

Bhagavad Gita: 7: 19:~ "Such a man who has attained true knowledge, the knowledge of Self, the knowledge of Atman, worships ‘Self’ as~ Atman (God) alone exists~ everything is Atman, there exists nothing except Atman. Such a man is extremely rare."

There are two kinds of audiences - the ordinary ones who desire the transitory heaven and other pleasures obtained as a result of ritual sacrifices, and the more advanced seeker who seeks to know the truth beyond the form, time, and space. The Bhagavad Gita is meant for the first audience, to help lead its followers along the way. The Advaitic wisdom is meant for those who wish to go beyond form, time, and space. 

Remember:~ 

The Soul, the ‘Self is the Infinite God. 

The Soul is the innermost Self. God is the Soul, which is present in the form of consciousness. God is the fullness of the consciousness without the illusory division of form, time, and space.  Therefore, there is nothing apart from it. 

God is Self-evident. God is not established by extraneous proofs. It is not possible to deny God because God is the very essence of the one who denies it. God is the basis of all kinds of knowledge, presuppositions, and proofs. God is within the universe in which you exist, God is without the universe in which you exist.

The Vedas confirm God is Atman (spirit), the Self.

Yajurveda – chapter- 32:~  God is Supreme Spirit has no ‘Pratima’ (idol) or material shape. God cannot be seen directly by anyone. God pervades all beings and all directions. Thus, Idolatry does not find any support from the Vedas.

Rig Veda: ~ 'Prajnanam Brahma'- Consciousness is the ultimate reality or Brahman or God in truth.

Do not accept any other God other than the Soul. The Soul is God in truth,  Nothing is real but the Soul, which is present in the form of consciousness. Nothing matters but realize  God in truth. God in truth is everywhere and in everything. Let these words be inscribed in your subconscious.

God in truth is hidden by the illusory universe. God in truth alone is real and eternal and all else is an illusion.

Brahman is merely a word to indicate the ultimate truth or God in truth.  The ultimate truth itself is God in truth.  

Rig Veda: ~ The Atman is the cause; Atman is the support of all that exists in this universe. May ye never turn away from the Atman the innermost self. May ye never accept another God in place of the Atman nor worship other than the Atman?" (10:48, 5)

Brihadaranyaka Upanishad: ~ Brahman (God) is in the form of the Athma, and it is indeed Athma itself.

People, who worship the belief of God, are hallucinating that they become one with such God.

Vedas itself says: May ye never accept another God in place of the Atman nor worship other than the Atman? Thus, to know the real God Self-realization is necessary. Self-realization is God-realization. Self-realization itself is real worship.

How can you worship God? That implies two ~ the worshipper and the worshiped, whereas God is nondual. One can worship his idea of God only or realize his unity with it when he can’t worship it as apart.

When Upanishads and Vedas declare that, “God is present in the form of the Athma, and God is indeed Athma itself” then why accept another God in place of the Atman nor worship other than the Atman.

God is the Supreme Being the One eternal homogeneous essence, indivisible consciousness and intelligence, which is beyond the form, time, and space. To which the Sages describe in a variety of ways through diverse words.

Sage Sankara’s wisdom is nothing to do with orthodox belief systems.

Some philosophers in the past dissented from this interpretation of Vedanta philosophy, holding that the Incarnated Souls were separate from the Divine Essence and only finally merged with it after the cycles of birth. All these theoretical philosophies are based on the imagination based on the false self (ego or you) within the false experience (waking).

It is quite easy to do this even by those who have never understood the Upanishads but think they have. Thus, the dualists and their disciples have written commentaries on scriptures: But all these have written to satisfy themselves, not to get the truth because all their interoperation are based on the dualistic perspective. The truth will reveal only when one is able to reason from the non-dualistic perspective.

Likewise, thinkers and poets of the Age of Devotion (Bhakti) of the 16th century believed in a God with attributes who became very tangible when incarnating as God and was attainable simply through love and devotion rather than scholastic and intellectual meditation.

For them, the Bhagavad Gita became the main vehicle of inspiration with its qualified and deistic Monism, rather than the scholastic and esoteric path shown by Sage  Sankara.:~Santthosh Kumaar