The body may destroy itself to verify if the mind will continue bettering itself without hardship. If we cannot prove that we can continue to grow and better ourselves without being forced to by outside forces, then we would be doomed to eventually fall in the face of adversity. We would stop growing. Our species would fall into atrophy and become irrelevant. Mortality has been necessary to ensure the survival and progress of our kind by providing a compelling motivator. We HAVE to live, because we can die. If we could not die, would we bother to continue living, even after millions of years?
If we maintain a forward momentum and deliberately move forwards, learning, bettering ourselves, living, if we managed this without being forced to by practical realities, we may win the right to immortality and take a step towards divinity. We may be mortal to ensure we learn volition. Once we learn we will evolve without having to do so through an iterative process.
Volition without need.
Change without compulsion.