BG 2.11: 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.
BG 2.12: 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.
BG 2.13: 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.