The man alone does not become Brahman (God) because the world in which man exists is mere an illusion. The illusion is created out of the Soul, which is present in the form of the consciousness. The consciousness is the ultimate truth or Brahman or God.
The Self is not you because you are bound by the experience of the birth, life, death and the world.
The experience of birth, life, death and the world is nothing to do with the Soul the innermost Self. When you are not the Self, then how can you relate the Self with your experience of the birth, life, death and the world. When the Soul wakes up with its own awareness, then you and your experience of the world becomes unreal same way as the dream becomes unreal when the waking takes place.
It is foolish to say ‘I AM GOD’ when the Self is not you, but the Self is the Soul. Therefore, the Soul, the innermost Self, is God.
People say Aham Brahmasmi ~ I am God, I am Brahman. But when Brahman is, how can "I" remain? Only Brahman remains, not the ‘I’.
The Bhagavad Gita: ~ Brahmano hi pratisthaham ~ Brahman (God) is considered the all-pervading consciousness, which is the basis of all the animate and inanimate entities and material. (14.27)
Rig-Veda 1-164-46 and Y.V 32-1 clearly mention that God is “One”.
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 innermost self. May ye never accept another God in place of the Atman nor worship other than the Atman?" (10:48, 5)
In Yajurveda – chapter- 32:~ It has been said that God Supreme or 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) is the form of the Athma, and it is indeed Athma itself.
People who are saying ‘I Am GOD’ are hallucinating that they become God. First, you must know what is God.
That is why Ashtavakra Gita 16:10:~ If you desire liberation, but you still say "mine," If you feel the ‘Self’ is the ‘I’, You are not a wise man or a seeker. You are simply a man who suffers.
Only religious Godmen declare: I AM GOD. Gnanis say the Soul, the innermost Self is God.