The waking experience consists of world including man is all one in the Self which is called Atman

The  waking experience consists of world  including man is all one in the Self which is called Atman. Atman means soul. The Atman is present in the form of consciousness. That Self when it appears behind the waking  or dream is called soul or Atman.

The same Self when it appears within the waking or dream as the body, is the soul. This very soul, therefore, is the Self in man. There is only one self, the Atman; thus self and over self one and the same.

The universe is Atman, the unbroken Atman; Atman is throughout the universe. "In everything and everywhere Atman pervades." The whole universe is Atman in its substance; Atman is both formed and unformed. Atman is everything; the manifestation of everything is Atman.

Brihadaranyaka Upanishad declares that:-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.

"Soul”, 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 innermost self. On the stand point the formless soul or consciousness, innermost self, there is no second thing exists other than consciousness.  Because the whole universe in, which we all exist is created out of consciousness.  There is no second thing exist other than consciousness. Hence it is nondual (non-duality). 

Deeper self-search revels the fact that, The soul(consciousness) ,body and world are one in essence therefore no second thing exists other than soul , which is in the form of consciousness.  Thus realizing all the three states as consciousness leads to self-awareness.

The Atman, the innermost self is within the illusion as its formless substance and it is without the illusion as its formless witness. The formless witness is the one which witnesses the body and universe together.  Thus the ordinary awareness is physical awareness (waking) is not self-awareness.  In self-awareness the body is not the body but it is the consciousness, the ego is not ego but it is the consciousness, the world is not the world but it is the consciousness even though they exist but their unreal nature is exposed. Just as the dream becomes unreal when waking takes place, the waking also becomes unreal when non-dual wisdom dawns.

The witness [knower] is that witnesses the coming and going of the three states. This truth has to be grasped mentally to realize the existence of the formless witness. Once this truth is grasped mentally, then one has to cling to the formless witness. Once one clings to this formless witness mentally than the subconscious has the yardstick to accept the truth and reject the untruth. Thus deeper self-search is necessary to understand, assimilate to have firm conviction of what is what in order to get self-awareness. 

Self-knowledge or Atma Gnana or Brahma Gnana cannot be attained by one who is without strength or earnestness or without the receptiveness and courage to accept the truth and reject the untruth. If a serious seeker strives sincerely by means of inquiry, analysis and soul-centric reasoning, he will be able to realize it.

It is only seekers sincerity and earnestness in his spiritual pursuit, the knowledge started revealing on its own.  Anyone who has humility and patience and is sincere and ready to drop their accumulated dross and receptive to accept the truth will enter nondual Self-Awareness when his conviction becomes firm.