Just what is the Bhagavad-gita? The purpose of Bhagavad-gita is to deliver mankind from the nescience of material existence. Every man is in difficulty in so many ways, as Arjuna also was in difficulty in having to fight the Battle of Kuruksetra. Arjuna surrendered unto Sri Krsna, and consequently this Bhagavad-gita was spoken. Not only Arjuna, but every one of us is full of anxieties because of this material existence. Our very existence is in the atmosphere of nonexistence. Actually we are not meant to be threatened by nonexistence. Our existence is eternal. But somehow or other we are put into asat. Asat refers to that which does not exist.

O descendant of Bharata, at that time Krsna, smiling, in the midst of both the armies, spoke the following words to the grief-stricken Arjuna. The Supreme Personality of Godhead said: While speaking learned words, you are mourning for what is not worthy of grief. Those who are wise lament neither for the living nor for the dead.

Never was there a time when I did not exist, nor you, nor all these kings; nor in the future shall any of us cease to be. As the embodied soul continuously passes, in this body, from boyhood to youth to old age, the soul similarly passes into another body at death. A sober person is not bewildered by such a change.

O son of Kunti, the nonpermanent appearance of happiness and distress, and their disappearance in due course, are like the appearance and disappearance of winter and summer seasons. They arise from sense perception, O scion of Bharata, and one must learn to tolerate them without being disturbed. O best among men [Arjuna], the person who is not disturbed by happiness and distress and is steady in both is certainly eligible for liberation. Those who are seers of the truth have concluded that of the nonexistent [the material body] there is no endurance and of the eternal [the soul] there is no change. This they have concluded by studying the nature of both.

That which pervades the entire body you should know to be indestructible. No one is able to destroy that imperishable soul. The material body of the indestructible, immeasurable and eternal living entity is sure to come to an end; therefore, fight, O descendant of Bharata. Neither he who thinks the living entity the slayer nor he who thinks it slain is in knowledge, for the self slays not nor is slain. For the soul there is neither birth nor death at any time. He has not come into being, does not come into being, and will not come into being. He is unborn, eternal, ever-existing and primeval. He is not slain when the body is slain.

O Partha, how can a person who knows that the soul is indestructible, eternal, unborn and immutable kill anyone or cause anyone to kill? As a person puts on new garments, giving up old ones, the soul similarly accepts new material bodies, giving up the old and useless ones. The soul can never be cut to pieces by any weapon, nor burned by fire, nor moistened by water, nor withered by the wind. This individual soul is unbreakable and insoluble, and can be neither burned nor dried. He is everlasting, present everywhere, unchangeable, immovable and eternally the same. It is said that the soul is invisible, inconceivable and immutable. Knowing this, you should not grieve for the body.