Immortality consists in not slipping from man’s natural divine state, namely, Brahman consciousness. If one does slip, that becomes the seed and cause of ignorance of the self within. This is death, for it becomes the further cause for future births and deaths.
The pursuit of sense objects by the gang of twelve (ten sense organs, mind and intellect) kills one. Then desire and anger take control of one. Immortality means coming out of all these and getting at the self. It does not mean transcending physical death.
If one is unattached to dualities like pain and pleasure, honor and humiliation, one will be earmarked for immortality.
Who is it that directs this atma, and what does it achieve? It is Brahman (Supreme Reality which is Paramatman.
Hunger and thirst belong to the vital breath; grief and delusion are of the mind; old age and death are of the body; none of these pertain to the atman.
Whatever karma (meritorious acts) one does, one reaps their fruit, and whatever sinful acts one does, one reaps their consequences also. The two coexist. The compensation is only in terms of vasana, the imprints left by the actions in the subconscious mind, not in terms of their fruit. The mere study of Vedas does not erase sins. The sins that one commits have to be atoned for and the consequences experienced. The study of Vedas will only point the way to salvation. Rituals are for purification of the mind.
Truth is one without a second. By enquiry into truth, one reaches the highest goal, moksha.
Whoever sees in all atmas his own self shall grieve no more. He would not need to go to any greater heaven than the bliss he enjoys in this knowledge.