Okay, this will probably be a little long, and a little… I don’t know, a little removed from everyday experience? But here goes:
The biggest reason I don’t believe there is a higher power that created the universe, or created us, is because the creation of the creator isn’t explained. In our universe, things build from simple to complex. If you start with a creator, then you start with complexity—they are a complex, conscious being with goals, intentions, and the ability to shape the material universe in ways that take tremendous energy. Where did they come from? Did they have a creator, too? Did their creator have a creator? If we need something before something in order to create something, if we need consciousness before consciousness in order to create consciousness, then how can there ever be an us? If, on the other hand, there is a mechanism for something to emerge for the first time, and for consciousness to emerge for the first time, why do we need the intermediary of a higher power/god to explain our existence? Why can’t the mechanism itself be the explanation?
There’s a fascinating theory/explanation for how the universe began from nothing. I’m sure I’ll butcher the explanation, but my layperson’s understanding is: During the Big Bang we get somethings from nothing when nothingness “splits” into particle-antiparticle pairs. Pairs pop into existence together, and when a set of paired particles collide, they annihilate each other, returning to nothing. This is a simple, consistent interaction (and from what I understand, has been replicated by scientists in labs). But there is a slight asymmetry, a slight inconsistency, in this process: a very small number of the antiparticles pop out of existence on their own, leaving their particle counterparts behind. From this glitch we get the matter that makes up our universe—the particles that were left behind. (From what I understand, this asymmetry has also be observed). Isn’t that just a beautifully absurd concept?
And from the left-behind particles we gradually get everything we know today. A simple thing runs into another simple thing, they interact in some simple way. Take enough simple things, let them interact enough times, and patterns may start to emerge—it doesn’t even need to be about hard-and-fast rules, just that certain ways of interacting may be more likely or more common (or, as with the asymmetry in the beginning, more consequential) and as a result, on aggregate, they are the norm. There is no plan, no predetermined rules, no inevitable ending point (and sometimes the errors and accidents are the driving factors of change, like how copying errors in genetics gives rise to the incredible biodiversity of life on Earth). Interactions simply happen. As they do, changes accumulate, complexity increases—incrementally, but look where it gets us after 13.8 billion years! It’s amazing. It’s spectacular.
This is how, for example, you get all the elements of our periodic table from hydrogen alone—hydrogen atoms gravitate toward each other, each attracting and being attracted by the others. The more hydrogen atoms there are closer together, the stronger the collective gravity. At some point, given enough atoms, and enough time for them to coalesce, the collective force becomes so great that the hydrogen atoms themselves start to break and reform into new things. These roiling masses of hydrogen are the forges for all the other elements in the universe. We call them stars. (Once again, I am very much a layperson—I’m sure that’s very far from technically accurate, but I think it’s the gist). How remarkable what can happen when a simple interaction—like atoms coalescing—continues for eons. And how remarkable that we, here and now, can study these patterns, describe them, and even predict them!
In one of the related questions, someone mentioned being awed by blue flowers quietly being blue flowers somewhere. I am also constantly awed by life, but not because I think there was a god behind it. I am simply awed by the existence of the flower. Or sometimes it’s a quiet morning when I see a spider in the corner, or my dog rests his head on my lap, or a squirrel frets away in the backyard, or for a moment I really notice my hand and think about the billions of years and countless generations of life before me that led to all of this. I am awed by the wonder and beauty of our remarkable, bizarre planet in our remarkable, absurd universe. I am awed by what can happen with a tiny asymmetry, and time. (And on the flip side, pain and destruction and injustice and the like make much more sense in a universe that came to existence indifferent and unaware, than in one that was carefully shaped by all-powerful hands… And even just the odd things about life make more sense, too. Life is, fundamentally, truly odd.) When I try to fit the idea of a higher power/god into this story, it always feels like I’m trying to wedge something into a story that works just fine without it, and doesn’t need it. If the universe doesn’t need it, then I don’t, either.
I want to note that I don’t begrudge or judge others for believing in a higher power, and I don’t think that belief in a higher power has to be at odds scientific inquiry, or threatened by it, or threatened by the idea of challenge and change.
On a related note, this comic: https://www.xkcd.com/505/
