The main message of Nisargadatta Maharaj's book "I Am That" is the realization of one's true self. Nisargadatta Maharaj, a renowned spiritual teacher and philosopher, emphasizes the importance of understanding and experiencing the true nature of oneself beyond the limitations of the mind and body.

Through his teachings and dialogues with seekers, Nisargadatta Maharaj guides readers towards the understanding that the true self is not the body, mind, or ego, but the pure awareness that exists beyond these temporary aspects of our being. He encourages readers to let go of their attachments and identifications with the external world and instead turn inward to discover the eternal and unchanging aspect of their being.

Nisargadatta Maharaj's message is one of self-inquiry and self-realization. He encourages readers to question their beliefs and perceptions, and to go beyond the conditioned mind to discover their true essence. He emphasizes the importance of being present and aware in the current moment, rather than dwelling on the past or worrying about the future.

The book also delves into the concept of consciousness and the role it plays in our existence. Nisargadatta Maharaj explains that consciousness is the source of all experiences and that it is the ultimate reality. He encourages readers to go beyond the limitations of the mind and tap into the pure consciousness that exists within.

Throughout the book, Nisargadatta Maharaj stresses the importance of self-inquiry and meditation as a means to understanding one's true self. He encourages readers to let go of their attachments, desires, and fears, and to simply be in a state of pure awareness.

Overall, the main message of "I Am That" is the realization of one's true self through self-inquiry, letting go of attachments, and tapping into the pure consciousness within. Nisargadatta Maharaj's teachings are a reminder that we are not separate from the universe, but rather an integral part of it. By understanding our true nature, we can find inner peace and live a fulfilling life.