No one can prove god’s existence. When an atheist states this obvious fact, they will almost certainly hear the response “well, but you cannot prove he doesn’t exist, either!”.
Agnosticism sounds reasonable then, right? You cannot prove god’s existence, you cannot disprove it, so you label yourself as “I don’t know” and... and you live your life as if there were no god. Almost as if you knew there’s none, but just didn’t want to admit it.
No one does it in regard to any other similar case. We cannot prove there are no unicorns, fairies or flying teapots orbiting the Earth, but do we label ourselves as fairy-agnostics? The notion that there are genies who grant three wishes is so absurd, that an educated person living in the XXI century either rejects it or becomes a subject of justified ridicule.
How is god different? That notion is so absurd, that since the moment I understood it, I would feel utterly ashamed not to reject it, too ashamed to hide behind the “nobody knows” excuse.
But most importantly: yes, you can. You can prove that there is no god.
How?
Just like you can prove there are no married bachelors, no hot coldness and no dry water. “Married” means “having a spouse”, “bachelor” means “not having a spouse” – you cannot be both at once. “Hot” means having high temperature, while “coldness” implies low temperature – nothing can be both at once. “Dry” means “lacking in liquid/moist”, while “water” is the precisely that liquid, which should be lacking in order to make something dry. Here, I’ve just “proven the negative”.
Different people define “god” to mean vastly different things, but I guess the majority of world’s believers would agree that their god is a person that created the universe, is omnipotent, omniscient, omnipresent, free, infinitely good, just and merciful. Possibly also spaceless and timeless?
Any god that has those attributes cannot possibly exist. He/she/it (let’s stick to “he” for simplicity), he would be self-contradictory.
To be omnipotent, he has to be able to do literally everything. But since he’s also omniscient, he already knows what he’s gonna and not gonna do. Can he do things he knows he will not do? If so, his omniscience was mistaken. If not, he’s not omnipotent.
Since he already knows all his future actions, can he at all do anything else? Either he doesn’t know everything, or has no free will. (Also: praying to him to change his mind is either futile or arrogantly interfering with his primeval, perfect plan).
Let alone the question how do we know god has all those attributes, but let’s ask ourselves, how does he himself know it? How does one know they’re omniscient? He might know a lot, he might not have yet stumbled upon a single question he doesn’t know the answer to. Yet. How can he be sure there’s nothing outside of his knowledge? To paraphrase our imaginary theist apologist: you cannot prove that there’s nothing he doesn’t know he doesn’t know, can you?
Mercy is, by definition, suspension of justice. You can either judge someone as they should be judged to even the offence they caused, or you can show mercy towards them and alleviate their punishment. Not both at once. (Unless you’re a married bachelor, maybe).
Also, infinite justice would require you to know and understand all the suffering and all the temptations that your accused was subjected to. Of course, god does know that, right? He’s omniscient, in the end. But can you really understand such issues, unless you have experienced them yourself? Would you feel judged fairly, if your judge has never been tempted, has no needs, has no limits, no problems, no weakness?
(If we focus on one particular religion, you could argue that god does indeed know all the struggles of being a human, since he came here as his own son and in a human form begged himself for forgiveness.... You know, two thousand years ago, while the human race exists since at least a hundred thousand. Ooooh, the timeline of god’s plan is a topic for a separate discussion... Long story short: it’s just another lame theological excuse.)
Being infinitely good, while having created a universe where evil exists, is also contradictory. If you’re omnipotent, therefore able to create any universe you wish, but you decide to create one with evil in it, then you and only you are responsible for that evil.
Our apologist would now certainly say that our universe is the best possible one, and if god removed some evil from it, some other one would emerge in a different place. And also that in order to have free will, we have to be allowed to do wicked things. (God, however, already knows what we’re gonna do, before we do it... So are we free or predestined? Make up your mind, finally!)
Ok, hands up, who deliberately does evil just because you can? Oh... apparently not that much, is it? Most of our evil-doing comes from the conditions we live in, that could easily be changed by an omnipotent being. God could’ve created the world with more natural resources and more fair distribution thereof, so that we didn’t have to work that hard and fight that much for them. God could’ve created us with weaker sexual desires. Or at least reveal himself, so that we make an informed decision about our beliefs. How could any of this lead to more evil, not less?
If suffering has to exist, because it makes us better human beings, how come the perfect god manages to be good without suffering?
And what the fuck are all the parasites and diseases about? Innocent children are dying in huge numbers every day, totally senselessly. It builds their character? Their suffering enriches the world around them? Please...
Also, since god is so omnipotent, cannot he create a universe with free will but without evil? Even if such universe would be self-contradictory – isn’t god self-contradictory as well? Or maybe such universe is possible, but the omniscient god doesn’t know he doesn’t know about it?
If he’s spaceless (being nowhere), how can he also be omnipresent (being everywhere)? And how could a spaceless, timeless, non-abstract being possibly be distinguished from anything else?
Also, if we just focus on Christian god: he has an arch enemy, Satan. What is even the point of the devil opposing god at all, if god knows his every past and future move, he knows Satan’s every plan, he is there when devil plans it, and is perfectly capable of doing literally anything! An omnipotent, omniscient, omnipresent god, who doesn’t destroy the devil, is responsible for the devil!
Phew!
So, to sum up: god such as proposed by the majority of believers, regardless of the particular version, is an idea so self-contradictory in so many different aspects, that it logically cannot exist.
God does not exist.
Quod erat demonstrandum.