Arjuna raises many questions to Krishna, and wonders how he can fight. Krishna tells him that he (Arjuna) speaks like a learned man, and yet he shows through his doubts that he is not learned. A truly learned man will know the distinction between body and atma clearly, and so he will not speak in this manner. The body is anyway going to be destroyed one day. It is perishable. So he will not worry about it.
The atma is imperishable. So he will not worry about that either. Every jivatma is the body of the Paramatma, and this body-soul connection between the Jivatma and the Paramatma must be properly understood, said Valayapet Ramachariar, in a discourse. So if we say that the atma is indestructible, then why do we talk of birth and death? What do these mean? Birth simply means that the atma occupies a particular body. When an atma has a connection with a body, we call it a birth. When the atma severs its connection with a body, it is death. But the atma always remains. It is never destroyed. This body cannot do anything on its own.
It cannot enjoy the fruits of action. The atma remains unchanged. It is a constant, not subject to any change. But the body moves from infancy to childhood, to middle age and finally old age. In the Ramayana, Kaikeyi very tactfully conveys the news of Dasaratha’s death to Bharata. She says Dasaratha has taken the path everyone eventually has to take. But her choice of words also shows the inevitability of the destruction of the body. It is this inevitability that Arjuna has not come to terms with, when facing Bhishma and Drona.
He does not want to be the one to kill them. He has not understood that he is only going to do so in the course of his duty, and that he is in no way causing the death of their atma, because the latter is impossible. The Lord’s advice to Arjuna was the purpose of the Krishna avatara, for the Lord came to show the world the paths to reach Him. The Gita holds the essence of the Vedas. The Vedas are not easily understood. They are like a huge building, which can be seen only if it is lit. The Gita is the light, which reveals the substance of Vedas.