The Atman (the Real) is deathless. It cannot be destroyed.
Death is an experience, not of the Atman, but of the body.
The body is subject to change, disease, old age, and death.
It has to be cast off like a worn out garment, so that the Atman may assume
other embodiments. For death is certain for the born, as is birth for the dead.
Thus grieving over death is futile.
The enlightened aspirant must realize that his right is to
work, and work alone. The fruits, the results of the work, should never be his
concern.
He whose mind is free from anxiety amid pains, indifferent
amid pleasures, loosed from passion, fear and rage, he is called a seer
illumined.
Chapter 2 of the Bhagavad Gita