Chapter 6 of the Srimad Bhagavad Gita is titled, “The True Yoga”. In this chapter, the teacher, Shri Krishna, teaches his pupil, Arjuna, the nature of True Yoga. It begins with the explanation of the true nature and spirit of renunciation, and the relationship of renunciation to desireless action.
The Atman cannot be cut, burnt, suffer any decay or be dried out. The five forces of nature which are capable of destroying physical elements by their combined actions have no influence on the Atman. That is why it is referred to as nitya or permanent or unchangeable.