Call for Proof
If somebody makes a claim that there is a God, the burden of proof is on them to prove that there is a God. If you really care about what you believe in as being true, you can’t just believe things on faith. If we did that, we would believe all kinds of whacky things, like aliens, Big Foot, leprechauns, unicorns, etc. With faith, you could make anything up (like a flying spaghetti monster) and claim it is true, just because you believe it. Saying, “Since you can’t prove it not true, then it must be true” is an argument from ignorance fallacy. That kind of logic just doesn’t work. Nobody can prove there is no God, but that doesn’t prove there is one.
Atheism is the default position. If you don’t choose to believe, you end up not believing. That’s why it’s not a choice. Atheism is not a belief. It’s a non-belief. You can’t turn your back on something you don’t believe to exist. If there is nothing, which direction do you turn your back to?
A good way to explain this is with the American justice system. When somebody is accused of a crime, it’s the prosecution’s burden of proof to prove him/her guilty. Nobody is required to prove they are innocent. We are all considered innocent until proven guilty. That’s the default position no matter if we committed the crime or not. It’s just like the default position to not believe in a God, no matter if there is a God or not. The jury can either decide that there is enough evidence to claim guilt or they can say there isn’t enough evidence, in which case they claim “not guilty”. No jury is required to claim somebody innocent. If there is exculpatory evidence that can prove innocence, like a solid alibi, the person shouldn’t be on trial to begin with. They can be found “not guilty” and still have committed the crime. (OJ Simpson might be a good example of that). In order for something to be believed to be true, you need evidence to back it up. Atheism is the default position, just like innocent is the default position. You’re innocent until guilt is proven and you’re an atheist until God is proven.
This only works if you actually care that what you believe in is actually true. If you just want to claim somebody guilty without evidence or claim there is a God without evidence, then what’s really true doesn’t matter.