That which fills everything completely from within and without is Supreme non-dual Brahman or God in truth.+

Sage Sankara: ~"That which permeates all, which nothing transcends and which, like the universal space around us, fills everything completely from within and without, that Supreme non-dual Brahman  (God)."

Thus, truth realization is Self-realization. The self-realization is God-realization.  God-realization itself is real worship.  

Some Gurus recommended repeating God’s name as a spiritual practice but what is the use of such practice without knowing ‘what God is in actuality.  Such practices are based on a religious God. Religious Gods are not God in truth.

God does not have a name because God is not an individual because God is the  Spirit. The Spirit is the root element of the universe. The Spirit is present in the form of the Soul, the innermost Self. The Soul is present in the form of consciousness. 

From the Spirit, the universe comes into existence. In the Spirit, the universe resides. And into the Spirit, the universe is dissolved. The Spirit is the parent of all that there is. 

 Bible says: ~ “God is a Spirit, and they that worship him must worship him in spirit and in truth. (John 4:24) 

Yajurveda – chapter- 32:~     God is is Supreme Spirit.

Vedas and Upanishad confirm the Soul, the Self, is present in the form of the Spirit or the consciousness.

Rig Veda: ~ The Atman (Soul or Spirit) 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)

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

When Bhagavad Gita says, God is considered the all-pervading consciousness 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.

If God is a formless Spirit, then how does man know God created the world? There is no proof. If man had seen God creating the world, he could admit it, but how could he have seen God before he came into existence? (i.e. were created).

The Spirit is the root element of the universe. The Spirit is present in the form of the Soul, the innermost Self. The Soul is present in the form of consciousness. From the Spirit, the universe comes into existence. In the Spirit, the universe resides. And into the Spirit, the universe is dissolved. The Spirit is the parent of all that there is. 

The religion preaches that God is one and the ways to God are many. It simply tries to lead them to darkness with its dogma and idea of many Gods, which is apart from the Self. 

People all over the world in the past and present accepted the idea of the existence of God.  The fear of God injected by the religion was the root cause of worship, superstitions, and dogmas.  The religious belief is passed on to the populace from one generation to the next generation

GOD, we do not see is real. God is hidden by the world in which we exist because the world in which we exist is created out of God.  From the standpoint of God, the world, in which we exist, is false.

In reality, the world in which we exist does not really exist and what does not exist for us, really exists.

Remember:~

By worshipping God in human form, repeating mantras is like watering a barren soil.  The seeker of truth should not waste life in empty formalities. Without realizing the world in which he exists,  is an illusion it is impossible to acquire Self-knowledge or Brahma Gnana or Atma Gnana.

The mantra-yoga consists of repeating the name of God, or even the AUM; thousands of times yield nothing. It can appeal only to the ignorant, to those who cannot think deeper. It is a mere religious fable. The real exercise is to think of the meaning of the name or the AUM and then only do you get something.

Mantras can do nothing. If they really had any power why did not Krishna use one to stop the Mahabharata war? All the magical power of mantras are a religious fable because religion is based on the false Self(waking or ego) and false experience(waking or world)        from the Standpoint of the Soul, the Self, the  Visions, and Samadhi are an illusion. 

That is why Sage Sankara: ~ VC- 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.

People of small intelligence follow religion and believe that the world was created by God. But how do they know that He did so? When a pot is created, one can see both pot and its maker, but not in the case of the world.

By believing and worshiping what is not truth (God), one is in the prison of the dualistic illusion.  Truth realization or Self-realization is God-realization. Self-realization itself is real worship. :~Santthosh Kumaar