Rig Veda clearly declares the God is Atman and never accept another God in place of the Atman nor worship other than the Atman.+

The religion of the Veda knows no idols. All the idols worshipped as Gods are non-Vedic Gods. If idols are of the non-Vedic Gods then why so many Gods and Goddesses with different forms and names are being propagated as Vedic Gods. Why these conceptual Gods are introduced when the Vedic concept of God is free from form and attributes.

Sage Sankara: ~ VC-  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 (verses-6)

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 Self. May ye never accept another God in place of the Atman nor worship other than the Atman?" (10:48, 5)

God and Goddesses worshipped in India today are non-Vedic Gods.   Such Gods and Goddesses cease to exist without the dualistic illusion. Whatever belongs to the dualistic illusion is bound to be an illusion.

Rig Veda clearly declares that God is Atman and never accepts another God in place of the Atman nor worship other than the Atman.   Then why worship any other God in place of the Atman, the real God.

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

When Bhagavad Gita says, God is considered the all-pervading consciousness (Spirit) which is the basis of all the animate and inanimate entities and material then nothing has to be accepted as God other than consciousness. 

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.

The dualistic worship of "God” is only for the ignorant populace. The God in truth is only Atman, the innermost Self.   In reality, there is no duality, no differentiation. Only Atman exists.

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

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.

Yajurveda says God is Supreme Spirit has no 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. Therefore, why worship the Gods when they cease to exist without the dualistic illusion.

This clearly indicates Vedic God is Atman, the innermost Self.   Thu, s Self-realization is God-realization. Self-realization is itself real worship.

Sage Sankara says: ~ Ataman is Brahman. Thus, the Soul the innermost ‘Self’ is God. Therefore,    all the Gods with form and attributes are mere imaginations based on the false Self.  Thus, there are adulteration and add-ons in the past, which has to be bifurcated if one wants pure Vedic essence.  

Yajurveda says they sink deeper in darkness those who worship what is not God: ~ 

Yajurveda

Translation 1.

They enter darkness, those who worship natural things (for example air, water, sun, moon, animals, fire, stone, etc).

They sink deeper in darkness than those who worship sambhuti. (Sambhuti means created things, for example, table, chair, idol, etc.) (Yajurveda 40:9)

Translation 2.

"Deep into the shade of blinding gloom fall asambhuti's worshippers. They sink to darkness deeper yet who on sambhuti is intent." (Yajurveda Samhita by Ralph T. H. Giffith pg 538)

Translation 3.

"They are enveloped in darkness, in other words, are steeped in ignorance and sunk in the greatest depths of misery who worship the uncreated, eternal Prakriti -- the material cause of the world -- in place of the All-pervading God, But those who worship visible things born of the Prakriti, such as the earth, trees, bodies (human and the like) in place of God are enveloped in still greater darkness, in other words, they are extremely foolish, fall into an awful hell of pain and sorrow and suffer terribly for a long time." (Yajur Veda 40:9.)

So, Yajur Veda indicates that:~

They sink deeper in darkness than those who worship sambhuti. (Sambhuti means created things, for example,  table, chair, idol, etc (Yajurved 40:9)

Those who worship visible things born of the Prakriti, such as the earth, trees, bodies (human and the like) in place of God are enveloped in still greater darkness, in other words, they are extremely foolish, fall into an awful hell of pain and sorrow and suffer terribly for a long time." (Yajur Veda 40:9.)

Brihadaranyaka Upanishad declares:~ "He who worships the deities as entities entirely separate from him does not know the truth. For the Gods, he is like a pasu (beast)". (1. 4. 10)

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

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.:~Santthosh Kumaar