In deep sleep we are aware of neither the body, nor of the world. Only in waking/dream we are aware of the body and of the world. Yet we are aware of the dual and non-dual experiences of all these three states. The three states are necessary to understand our true existence.
We experience duality only in waking and dream, whereas we experience non duality in deep sleep state. Many of us associate the all the three states is an experience limited only to the physical body. This is the cause of the ignorance. We are ignorant about the existence of the formless witness [knower] which witnesses the three states.
When deeper inquiry, analysis and reasoning revels the fact that, neither the physical body, nor the `I', is the true self , then how can we say all the three states is experience of the physical body. In waking we experience the waking entity and waking world, and in dream we experience the dream entity, and dream world, and in deep sleep there is neither the entity nor the world.
Therefore, it is necessary to verify the facts about the formless entity which is aware of the three states without any break. There has to be the one witness, which witnesses, the three states, and is fully aware of these three states, which appear and disappear in succession.
The waking entity and the waking world are absent in the dream, likewise the dream entity and dream world are absent in waking. And waking and dream experiences are absent in deep sleep. Therefore we have to hold all these as mere experiences, which comes and go, like the train comes to the station and goes. The formless witness is like station and it is unaffected by the coming and going of the experiences.
From this we can come to conclusion our experiences [three states] are like a motion picture and the witness [consciousness] is like a screen. The screen is unaffected by whatever is projected on it. The screen, that gives power for these experiences. Without the screen, there is no experience of any sort. The experiences are insentient, but the screen is sentient. The screen can remain with or without the experience, but the experience is dependent on the screen for their existence.
Until one thinks all the three states are as his own experience, he is bound to remain in ignorance. From the spiritual point of view, the level of one's spiritual maturity determines how one sees 'worldview ' whether as form [I] or formless [I –less]. When one sees the worldview on the base of form, the physical body and the world, seems to be real, and the duality is experienced as reality. But when one is able to view it on the base of formless self [consciousness] one becomes aware of the fact that the whole experience of diversity is nothing but Ataman, because there is no second thing exist other than consciousness. Thus the duality is mere mirage on the base of formless self.
The consciousness is always consciousness, for some, consciousness is form [god] and for others consciousness is formless! Consciousness is above all attributes and the spiritually speaking, God is the intellectual perception of consciousness, and formless self or consciousness is beyond the human perception