First, you must know what God is supposed to be then only you will realize you and the world in which you exist merely an illusion created out of the Soul or God.+

God cannot be brought down to the domain of duality. There is only one being in reality, and it is the Soul, the Self, which is present in the form of consciousness.

The Soul, which is present in the form of consciousness pervades in everything and everywhere in all three states. Thus, the Soul or consciousness is the ultimate truth or Brahman or God in truth.

When one realizes the form, time and space are one in essence. And that essence is the consciousness, then he realizes there is no second thing that exists other than consciousness. Thus, everything is consciousness. 

Thus, consciousness is the ultimate truth. And the ultimate truth or Brahman or  God in truth.

Holding the religious belief that God keeps the Soul, the Self permanently in ignorance. Ignorance keeps the Soul permanently in the prison of dualistic illusion. 

The 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 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 practicing 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 has 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 most advanced seekers who seek to know the truth beyond form, time, and space. 

Religion and yoga are meant for the first audience, to help lead its 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 then only you will realize you and the world in which you exist are merely an illusion created out of the Soul, which is God in truth.

Religions are based on personal Gods based on blind belief whereas Sage  Sankara’s Supreme Brahman (God in truth) is impersonal, Nirguna (without Gunas or attributes), Nirakara (formless), Nirvisesha (without special characteristics), immutable, eternal, and Akarta (non-agent). God in truth is above all needs and desires. God in truth is always the Witnessing Subject. God in truth can never become an object as God in truth is beyond the reach of the senses. God is non-dual, one without a second. God in truth has no other besides it. God in truth is destitute of difference, either external or internal. God in truth cannot be described because the description implies a distinction. God in truth cannot be distinguished from any other than God in truth. In God in truth, there is not a distinction between substance and attribute. Sat-Chit-Ananda constituted the very essence or Svarupa of God in truth, and not just God's attributes. The Nirguna Brahman of Sage  Sankara is impersonal.

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 is 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 in truth) 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 in truth) 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