Brihadaranyaka Upanishad:~Brahman is the form of the Athma, and it is indeed Athma itself.+

Brihadaranyaka Upanishad:~  The Self is indeed Brahman, but through ignorance, people identify it with intellect, mind, senses, passions, and the elements of earth, water, air, space, and fire. This is why the Self is said to consist of this and that and appears to be everything. 

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

DVI" means two. DVI" connotes dual existence and the non-dual. Which of these two is non-existence? People think that there is God and that the jivas--souls-- like them form the second, other than them. There is no such duality at all.

The  Soul,  the Self, which is present in the form of consciousness, is the only reality and there is nothing other than this soul or consciousness, which is the  Self. 

From the standpoint of the  Soul, the Self, there is no second thing that exists other than consciousness.  Because the whole universe in which we all exist is created out of consciousness.  There is no second thing that exists other than consciousness. Hence, it is nondual (non-duality). The soul or consciousness is the ultimate truth or Brahman or God in truth.    

People say Aham Brahmasmi ~  I am God, I am Brahman. But when Brahman is, how can "I" remain? Only Brahman remains, not I.

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

To say there is God or no God, you must be present. You are present only when the world is present. Without you, the world ceases to exist. Thus,  you and the world appear together and disappear together. 

A deeper investigation reveals the fact that there is no use in inquiring “WHO AM “I ?  because you are inquiring only about your existence dropping the world in which you exist. Without including the world in your inquiry it is impossible to realize the Advatic Truth, which is beyond the form, time, and space.

That is why Sage Sankara said:~  VC-63- Without causing the objective universe to vanish and without knowing the truth of the Self, how is one to achieve Liberation.

That is why Sage Sankara says:~VC 65- As a treasure hidden underground requires (for its extraction) competent instruction, excavation, the removal of stones and other such things lying above it and (finally) grasping, but never come out by being (merely) called out by name, so the transparent Truth of the self, which is hidden by Maya and its effects, is to be attained through the instructions of a knower of Brahman, followed by reflection, meditation and so forth, but not through perverted arguments.

66. Therefore, the wise should, as in the case of disease and the like, personally strive by all the means in their power to be free from the bondage of repeated births and deaths.

Thus,  one has to know what is real by realizing our body and our experience of the world is merely an illusion created out of consciousness, which is the Self.  The nature of the self is emptiness. And it is identified by different masters with different names such as God in truth or Brahman or consciousness. :~ Santthosh Kumaar