Atheists, tell me, a Roman Catholic: why should I become an atheist?

[Vincent]

Atheists, why do you reject the idea of God, and why should I? I know that your answers will include "there's no evidence" and all that, but please try to explain.

Hey bud. Don't know if you're planning on coming back to this thread, but I'm going to toss my thoughts into the mix. 

First of all, I can't tell you what to believe. I do not much like the religion you follow, but it's not my mission to de-convert you. Follow what feels right. 

That aside, I can offer you my own journey to atheism. I was raised in a household where the Christian god was believed in but not actively worshiped. We did not read the Bible or attend church. Most of my religious experiences came from spending time with my grandmother, who was a devout Baptist. Nothing that happened to me drove me away from the religion; I was overall apathetic to it. I considered myself agnostic through much of my adolescence. It wasn't until I entered college that I gave further thought to the god idea, and I started asking serious questions. 

I remember staring up at the stars one night. It had never occurred to me before just how small Earth and humanity are, and how overwhelmingly large the universe was. I looked up, and I saw so many stars. Hundreds. More than I could count. And each star was billions of miles away, and each one had planets orbiting around it. There were millions of other solar systems out there, millions of celestial bodies and millions of miles of space between them, just in our galaxy alone. And our galaxy, too, was just one in billions. Our planet is no more significant than a grain of sand on a beach. 

I guess I always knew that, but fully contemplating it made me ask: How can humanity be the centerpiece of any diety's plan, when we were no more than one mutated species on a tiny speck of dust in an incomprehensibly vast universe? Why were there billions and billions of other planets out there, almost all of which are completely uninhabitable to us? Why are there billions of other galaxies, billions of other suns, billions of other solar systems, and here we are, on this one, tiny planet? What is the purpose for all the rest of it? I searched for an answer to this question, and the only response I kept getting was "the rest of it was for the glory of god, like him playing around with the universe before creating us". That didn't satisfy me. He could make whatever he wanted, but instead of making other worlds of beauty and life, he made virtually everything off our planet desolate and inhospitable. Environments that would kill us if we took one breath of its air. And most of it is just empty space, empty space that we cannot survive in without complex scientific equipment. We cannot populate 99.9% of the universe. So, what then, god just put it there for the looks? 

And another question came to mind. If a being existed that was so vast and powerful it could create a universe as large and infinitely complex as the one we exist in... why the hell would that being care about humanity? To such a being we would appear as less than ants, and yet it would go through the trouble of writing a book, of creating a "son" in the form of one of us, of judging us for our behaviors, of caring who we slept with, of caring whether we worshiped it? No. That was nonsensical to me. If a god created this universe, this universe so so big, it would not give a single fuck if an ape descendant got on its knees and prayed to it. Such a being would not require validation from something so small. Believing that we are that special, that a god would care about us, was arrogance on the part of our species. It was humanity looking for meaning in its own existence, looking for some reassurance that we are not just evolved animals that came about through various mutations and millions of years of natural selection. 

But that was not the only thing driving me from theism. I came to an understanding that the afterlife probably did not exist. I figured that everything we are, everything that makes us us, is entirely a product of our brains. Our personality, our memories, our fears, our emotions, our hopes, our motivations, our ability to comprehend language and solve complex problems and make connections... all of that can be explained with a course in physiology and psychology. It's all a result of completely material processes. And it ends, every single bit of it, when we die. Our brain shuts off, our body stops functioning, and we are gone. The brain does not transcend to a different state of being; there is no afterlife for it. It just... stops. And if that is the case, then what is carried into the afterlife? It can't be us, because the thing that made us who we are is gone. I began to realize that the afterlife was a story, created by humans frightened of death, of a life that ends when our mortal bodies do. I've heard it said that animals have no soul, that there is no afterlife for them, not in Christian theology. Why are we so different? Because our brain is more advanced, because we are more evolved? That doesn't prove the soul's existence, and thus it doesn't prove an afterlife. There is no reason to believe in a soul aside from the fact that a book is telling you to. And without a soul, without the afterlife, the Christian god's entire existence is thrown into serious question. 

But beyond even that, I contemplated a world where there was no god, and what such a world would look like. I imagined it would be filled with harsh, barren planets, life capable of existing on only a scarce few. I imagined it would be filled, most of it, with empty, useless space. I imagined it would run on completely observable systems, on natural processes that could be tested and understood. I imagined that "miracles", or instances of suspending the natural order, would be few and far between. And I imagined that defying the natural order would be impossible (example, a human amputee spontaneously waking up with a limb regrown, or a certified dead person walking around the next week with no other apparent reason than that someone prayed for it). I imagined that life would only come into existence through struggle, through survival of the fittest, through many species dying out mercilessly because they were not strong enough to make it, leaving only the most adaptable to breed and pass on their genes. I imagined that if an intelligent species eventually evolved, it would very likely turn to magic and mysticism to answer the questions it had. I imagined such a species would proclaim storms to be the work of the gods, and the seasons to be the work of the gods, and the sun and the moon to be the work of the gods. I imagined, as that species grew older, and matured, the gods it believed in would change and evolve, with many falling out of memory and others taking up fame and popularity, much like a free market economy. I imagined, as that species learned more of the world it inhabited, its gods would turn into, as Neil Degrasse Tyson so eloquently phrased it, "an ever receding pocket of scientific ignorance". I imagined that believers in these gods would look for solid evidence for their deity, but find none, and thus be forced to turn to supernatural claims that could not be proven or disproven, and unreliable or biased anecdotal evidence to support the existence of such a being. 

I imagined a world just like ours.

I cannot say for a certainty that no god exists, as I do not know everything. But thus far in my life, I have looked at the world and drawn the conclusion that there is probably not a god, in the same way that there are probably no unicorns and elves.