The objective of the statement “aham brahmāsmi” is to remove the attachment with physical body.
In Upanishads many statements ( Mahavakyas ) like ” Tat tavam asi ” or “ayam ātmā brahma” is mentioned and their purpose is remove the attachment to this physical body and understand one’s real nature, which is Atman.
What is our definition of God ?
- We interpret God as worldly god (like Indra, Krishna, Shiva e.t.c ) who will bless people with their super power or make their wishes come true.
- God is one who make this world perfect place to live, by blessing the one who suffers or who are deprived
Vedanta talk about a formless God who is creator and source of this world, but he is not a physical body.
Vedanta never consider this world as real, so there is no need for a worldly God to make this world perfect.
Mahavakyas talk about Atman ( also called as God or Brahman), who is source of this world. Vedanta says that the Atman himself is experiencing this world, and thinks that he is stuck in this world.