If one does not believe in another life or an afterlife, life itself might be the most precious thing there ever was.
Just think about the astounding circumstances that have brought your or my specific mind into existence.
Given the uniqueness of every mind on this planet we all should feel honored to be alive with them at the same time.
But what do we do? We make people lives miserable. We waste lives in wars. We let children starve before they even have to chance to use this ordinary gift.
I think future generations will judge us for this.
But then, most people live crap lives.