Acharya Prashant explains that the human body is a product of nature, similar to animals and plants, and possesses a specific lifespan. However, humans are distinct because of the ego, which is a powerful element of nature seeking liberation through human consciousness. The ego, also referred to as the individual soul or 'Jivatma' in the Bhagavad Gita, is not the eternal Truth or Atma but is a manifestation of nature and ignorance. It remains attached to the body and society because it seeks immortality through long life and fame, which are false substitutes for the true immortality found only in the Atma.