Bhagavad Gita, Chapter 2, Verse 18

Of this indwelling Self, the ever-changeless, the indestructible, the immeasurable, these bodies are said to have an end. Fight therefore, O descendant of Bharata.

Your body will end one day. You won't. Now go do what's yours to do.

Everything about this body - what it's made of, how it got here - is temporary and replaceable. What lives inside it isn't. So act, without confusing the two.