There is a lot of confusion, and many misconceptions, surrounding the concept of “immortality”. The popular conception involves expecting some kind of mysterious process to allow us to “live forever” in the current body. This of course, has no realistic meaning behind it. Many people have explored the variations on this theme over the years and determined that such a persistence would be meaningless and would in fact lead, not to upward progress, but to stagnation. The aspiration to overcome the power of Death is what drives this concept in its various forms.
The Bhagavad Gita, as would be expected from a deep and subtle teaching, takes a different approach to the question of immortality. Sri Aurobindo introduces the Gita’s conception of immortality: “The man who rises above the conception of himself as a life and a body, who does not accept the material and sensational touches of the world at their own value or at the value which the physical man attaches to them, who knows himself and all as souls, learns himself to live in his soul and not in his body and deals with others too as souls and not as mere physical beings. For by immortality is meant not the survival of death,–that is already given to every creature born with a mind,–but the transcendence of life and death.”
This brings us to Arjuna’s situation within the context of the teaching Sri Krishna is providing to him: “Whoever is subject to grief and sorrow, a slave to the sensations and emotions, occupied by the touches of things transient cannot become fit for immortality….To be disturbed by sorrow and horror as Arjuna has been disturbed, to be deflected by them from the path that has to be travelled, to be overcome by self-pity and intolerance of sorrow and recoil from the unavoidable and trivial circumstance of the death of the body, this is un-Aryan ignorance. It is not the way of the Aryan climbing in calm strength towards the immortal life.”
Sri Aurobindo, Essays on the Gita, First Series, Chapter 7, The Creed of the Aryan Fighter, pp. 56-57,