There is clear-cut idea in the scriptures, what supposed to be God. And what not to worship in place of God.+

Holding the blind belief as God keeps the Soul, the Self permanently in ignorance. The ignorance keeps the Soul permanently in the prison of dualistic illusion. Illusion makes the Soul remain in the domain of form, time, and space. 

In the domain of form, time, and space the experience of birth, life, death, and the world is experienced as a reality.

If the seeker wants to realize the truth, then he has to discard all the religious beliefs and yogic practices, and scriptural studies. Nothing is needed in pursuit of truth other than an intense urge and receptivity to realize the truth, which is beyond form, time, and space.

That is why 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)

Sage Sankara said: ~ -Neither by the practice of yoga nor philosophy, nor by good works nor by learning, does liberation come, but only through the realization that Atman and Brahman are one in no other way. (1) Vivekachoodamani v 56, pg~25

Sage Sankara’s wisdom is nothing to do with religion and yoga. 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. Religion and yoga are meant for the first audience, to help lead their followers along the way. Sage Sankara’s Advaitic wisdom, with its emphasis on the Advaitic wisdom, is meant for those who wish to go beyond such transient pleasures.

First, you must know what God is supposed to be.

There is a clear-cut idea in the scriptures, of what is supposed to be God. And what not to worship in place of God then why worship the belief of God, which not God in truth.

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.

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)

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)

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.

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 declares: 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