Two most popular answers to this question at divineatheist.quora.com from a theist’s and an atheist’s perspective:
From a Christian’s perspective:
No, they can’t but you also can’t prove He does exist, so why don’t you just stop with this exhausting stalemate?? Why do you care? Let them believe whatever they want. Seriously.
Are you trying to get them to convince you? What’s going on here? Kinda looks like your faith is weak. This is ridiculous at this point. It’s small minded. You really think you’re going to come to an entire group of atheists and make a dumbass comment like that and get anything accomplished?
I’d literally my entire bank account that you cannot provide a single shred of evidence to backup your claim and the burden of proof is on you bro. Still a Christian here but I’m also a very science minded individual that knows a lot more than most people about all this. You do more damage than good with garbage like this. Yes, I absolutely believe in God, I know He’s real, but I also know that lots of other people believe in other gods. Which God are protesting is real here anyways? There’s gotta be a thousand of them.
Maybe try having smarter conversations to start. You’ve gotta be the hundred thousandth person to make this ridiculous post and I’m sure they’ve blocked an equal amount of them. My actual pastor is a Baptist pastor, I come from a slightly more conservative church. Him and I both have plenty of atheist friends that we chat with about this stuff. And Buddhists and Hindus and Muslims and other religions that you’d have to Google to even know what I’m talking about. For fucks sake, I don’t even know if we have an accurate count on how many Gods 7 billion, pushing 8, believe in. Knock this crap off, brother.
You ever tried actually having a conversation with a true atheist about why they don’t believe in a God or do you always just open with forcing your belief on them and then demanding they prove you wrong? There’s an amazing amount of intelligence in this group, maybe try learning something. I freaking cannot stand ignorance. There’s so many different backgrounds and educations in this group that you’re really missing out on what it’s actually about with this nonsense.
I’m Eric, I’m a Christian, not an idiot, and I cannot stand ignorance like this. I do personally believe in God and I have my own personal reasons why I do and I’m happy to engage anybody if reasonable intelligence in civilized conversation about the topic. I’ll respect your beliefs and you’ll respect mine and we both might learn something we didn’t already know. It doesn’t have to change our personal beliefs, it can just be new information and nothing more.
I don’t need you guys to believe in my God though, feel free to believe what you believe. I’m sorry you have to deal with posts like this.
Harald Imre
From an atheist’s perspective:

What Tyler