Chapter 2 · The Yoga of Knowledge · Krishna said
Bhagavad Gita 2.27 — Death is certain
जातस्य हि ध्रुवो मृत्युर्ध्रुवं जन्म मृतस्य च। तस्मादपरिहार्येऽर्थे न त्वं शोचितुमर्हसि ॥
jātasya hi dhruvo mṛtyurdhruvaṃ janma mṛtasya ca | tasmādaparihārye'rthe na tvaṃ śocitumarhasi ||
Meaning
Death is certain for one who is born, and birth is certain for one who dies. So you should not grieve over what cannot be avoided.
In today's life
Accept what cannot be changed, and put your energy into what you can still do.