The question is whether Nature actually deserves a religious response. Traditional theism has to wrestle with the problem of evil: if God is good, why does he allow suffering and death? But Nature is suffering and death. Its harmonies require violence. Its “circle of life” is really a cycle of mortality. And the human societies that hew closest to the natural order aren’t the shining Edens of James Cameron’s fond imaginings. They’re places where existence tends to be nasty, brutish and short.
Religion exists, in part, precisely because humans aren’t at home amid these cruel rhythms. We stand half inside the natural world and half outside it. We’re beasts with self-consciousness, predators with ethics, mortal creatures who yearn for immortality.
The "we" here is a bit tendentious, but certainly many people have these strong longings for something beyond the world we can see and touch: for ultimate answers, for an escape from death, for moral laws backed by divine anger. For nonbelievers, the existence of the "god-shaped hole" in the souls of many humans is one of the greatest puzzles. It seems a cruel trick for the universe to equip us with longings for what does not exist.
I would observe, though, that if life among hunter-gatherers is often short, it is not necessarily more brutish or nasty than any other sort of human life. Nor does belief in God do anything to lengthen it; the medieval world was every bit as nasty and brutish as the Mesolithic, and life might even have been shorter. And that is how I also feel about our spiritual situation. For me, religion doesn't really explain anything about the place we find ourselves in. It simply changes the questions. The fact of my existence on this world at this time, born with certain strong inclinations, surrounded by the others beings I have fallen in with, remains an absolute mystery to me no matter how I think about it. The "answers" offered by the religions I know seem to me either evasive or unhelpful. I don't expect any "answers" from science, either, not about the really hard questions.