"The Way of Cross and Dragon" by George RR Martin has some relevant themes.

You can either read it in the anthology "Dreamsongs," or just click here

Excerpt (mildly spoilery):

"We Liars, like all other religions, have several truths we take on faith. Faith is always required. There are some things that cannot be proved. We believe that life is worth living. That is an article of faith. The purpose of life is to live, to resist death, perhaps to defy entropy."

..."We also believe that happiness is a good, something to be sought after.".... "The Liars believe in no afterlife, no God. We see the universe as it is, Father Damien, and these naked truths are cruel ones. We who believe in life, and treasure it, will die. Afterward there will be nothing, eternal emptiness, blackness, nonexistence. In our living there has been no purpose, no poetry, no meaning. Nor do our deaths possess these qualities. When we are gone, the universe will not long remember us, and shortly it will be as if we had never lived at all. Our worlds and our universe will not long outlive us. Ultimately entropy will consume all, and our puny efforts cannot stay that awful end. It will be gone. It has never been. It has never mattered. The universe itself is doomed, transitory, and certainly it is uncaring."