Existence is meaningless and we just wobble around here for a little while and then we die. There's nothing to it. Everything that happens is just a logical consequence; beauty is nothing but a tiny chemical reaction in your brain. Once you rot it's all worthless.

Science is great at giving explanations, but not so good at providing meaning. For a lot of people, meaning is probably more helpful in order to facilitate a happy life.

Nietzsche writes at length about this stuff, most famously in the anecdote about the madman coming down from the mountain to inform the villagers that God is dead and that we have killed him. Everybody knows the three words "God is dead", but I think it's worth reading at length:

God is dead. God remains dead. And we have killed him. How shall we comfort ourselves, the murderers of all murderers? What was holiest and mightiest of all that the world has yet owned has bled to death under our knives: who will wipe this blood off us? What water is there for us to clean ourselves? What festivals of atonement, what sacred games shall we have to invent? Is not the greatness of this deed too great for us? Must we ourselves not become gods simply to appear worthy of it?

Nietzsche, whose father was a priest, recognizes that "God has become unbelievable", but he does not celebrate it as the progress of science. Rather, we lost something that was fundamentally important to humans, and which science cannot easily replace.

Here one could start talking about the Free Masons, who attempted learning from religious rituals without the added layer of religion. Or one could dig deeper into the works of Nietzsche, and the contrast between Apollonian and Dionysian. It's all fascinating stuff.

In short though, spirituality used to offer people a sense of meaning that is not so easily replaced by science alone. How do we bury our dead now that we know our rituals are pointless?