So far, the answer has been "no." But I keep asking, because I'm always interested in the replies I get.
Frequently, I'll get an argument from ignorance: "Well, where did everything come from, if not from God?" But just because we don't know everything, that doesn't mean you can just make up your own explanation.
Centuries ago, we didn't know what the Sun was, so people decided that it must be a god - perhaps driving a golden chariot across the skies. The big theological question back then was, "Where does the Sun go at night?" Yes, that was a... burning theological question (if you'll excuse the pun) for centuries.
Well, if the Sun wasn't a god, what was it, then? Proto-scientists couldn't explain it, therefore it must be a god, right? Wrong. That's an argument from ignorance.
Often, I'll get 'evidence' that's not really evidence at all. The Bible, for example, isn't evidence. Nor is the Koran, or any other 'holy book.' If you think that one of them is evidence, do you think that all of them are evidence? I doubt it.
Feelings aren't evidence, either. Feelings exist, certainly, but they can be easily explained as delusion or wishful-thinking (and simply as human nature, since believers of all religions feel that their religion must be true).
Unusual events aren't necessarily evidence, either, even if they can be documented and independently verified (which is rare). In a world of 7 billion people, with uncounted numbers of events happening every second, unusual events are the norm. Learn statistics.
So if you can't use evidence - because you don't have any - to back up your beliefs, what can you use? Well, there's always philosophy, right?
(Saturday Morning Breakfast Cereal)
OK, you can probably see what I think about philosophy. :) I tend to agree with PZ Myers when he says this:
What’s missing in philosophy is that anvil of reality — that something to push against that allows us to test our conclusions against something other than internal consistency. It means philosophy is excellent at solving imaginary problems (which may be essential for understanding more mundane concerns), while science is excellent at solving the narrower domain of real problems. Science has something philosophy lacks: a solid foundation in empiricism. That’s a strength, not a weakness.
Science is evidence-based, which keeps it grounded in the real world. That's why science advances. That's why we've seen such incredible progress in science, because each step is built on a firm foundation of evidence.
Philosophy doesn't have that. Philosophy can build an imposing logical structure, but if it's all built on sand, it's just imaginary, not real. Sure, if you want to admit that your god is just imaginary, you'll get no argument from me. But if you want to claim that he's real, that's different.
I'll admit right from the start that I don't know much about philosophy, so that's not going to be my main argument here. However, when people tell you that they can prove God exists, they're normally talking about philosophical proofs.
Science is about evidence, not proof. In science, nothing can be "proved" to the extent that contrary evidence would be disregarded. In science, everything is open to further investigation.
I go further and claim that we can't actually "prove" anything when it comes to the real world. Can we prove that the Earth is round? How do you know that the Earth exists at all? We could all be living in a computer simulation. Or you could be a brain in a bottle, just hallucinating all this.
And if you accept the possibility of an omniscient, omnipotent god, he could do anything - by definition - including convincing all of humanity that the Earth is round, rather than flat. (Maybe God just has a weird sense of humor? At any rate, "God works in mysterious ways.")
No matter how much evidence we have, there are always other explanations which could be true. It's very unlike that they are true, though. And as a practical matter, if you expect to live any kind of rational life, we really need to go with the evidence.
So when religious apologists claim they can "prove" that their god exists, they're usually talking about philosophical proofs. Professional apologists produce slick videos and use clever patter in practiced debates, where they use arguments which sound very impressive to the uninformed. Well, how many of us know much about philosophy? Not me.
You can research the most common arguments - the ontological argument, the cosmological argument (and a variant, the Kalam cosmological argument), the transcendental argument, etc. - if you find that sort of thing interesting. Iron Chariots.org is a good resource for this.
As these arguments are refuted, they tend to get revised by apologists who simply believe what they believe and are desperate to convince you, too. If their arguments are proven wrong, they'll just find new arguments. But the old arguments never go away, because they remain useful to convince the ignorant. (They still sound impressive if you don't know where the logical fallacies lie.)
And believers - including anonymous commenters here - will often cut and paste arguments which they, themselves, don't understand. They've seen it elsewhere, and it sounded impressive. More to the point, it seemed to back up what they want to believe (almost always, what they were raised to believe).
Sure, you can check out Iron Chariots.org for reasons why a particular philosophical argument is wrong. You can even study philosophy yourself, if that's what you want. But I'm not particularly interested in philosophy, and it seems to me that there are easier ways to refute such nonsense.
As I noted, I prefer science, rather than philosophy, because science is evidence-based, and that keeps scientists grounded in the real world. One of the big results of that is that scientists regularly come to a consensus on scientific issues.
We don't see different conclusions depending on whether a scientist was born in India, in Italy, in Russia, or in Mississippi, but rather a consensus among scientists worldwide who've all been convinced by the evidence.
This doesn't mean that every single 'scientist' agrees (they're still human), and there's not a consensus on everything (if there were, we'd already know everything, so there'd be no need for further scientific research). But scientists do come to a consensus, because they're evidence-based.
So when it comes to questions of science, I don't have to be an expert in everything (which is impossible, anyway). I just have to understand the scientific method well enough to accept the scientific consensus, if there is one. (If there isn't, I simply reserve judgment.)
But what about questions of philosophy? Philosophy isn't evidence-based, so it's not grounded in the real world. And the result? Look at this poll of philosophers. Do you see a consensus on anything? They can't even get a simple majority to agree on many of those issues, and rarely much more than that.
So if you're going to 'prove' something using philosophy, you first need to explain why philosophers can't even agree among themselves, don't you think? Philosophers are the experts when it comes to philosophy. So what does it tell you when they can't even convince other philosophers?
And the really funny thing, when it comes to using philosophy to 'prove' God, is that one of the biggest areas of agreement among philosophers is that gods don't exist. That poll indicates that nearly 73% of philosophers are atheists (a very high percentage, compared to the lack of agreement among most other issues, don't you think?) versus only 15% who are theists. (Those theists, of course, include believers in all sorts of different gods, not just the Christian one, let alone the particular god of a particular Christian sect.)
So when a Christian apologist claims to be able to prove that God exists - his own god, of course - using a philosophical 'proof,' do you really need to refute that argument? Or can you just ask why, if what he's saying is true, that philosophers themselves overwhelmingly disagree?
Similarly, I'll frequently hear Creationists claim that they can disprove evolution. And if you don't know much about evolution yourself, maybe you'll believe them. But biologists - the experts in that particular field of expertise - overwhelmingly disagree.
When the people who know the most about a particular scientific issue are the least likely to agree with you, what are the rest of us to think? When you can mostly convince people who don't have a clue - people with little education and no background in that particular field - what does that say about your argument?
Well, this is the same way. Philosophers don't come to a consensus the way scientists do, and that's one reason to be wary of philosophical 'proofs' in the first place. But when you can supposedly 'prove' that God exists using philosophy, please explain why philosophers overwhelmingly disagree with you.
What you'll find is that these Christian apologists only convince the ignorant. Rather, they only convince people who already believe in that particular god. None of those people have been convinced by the argument itself, because they already believe for other reasons (normally, because they were raised to believe it, so they really, really want to believe it).
For the rest of us, it's hard to take a philosophical argument seriously when philosophers themselves overwhelmingly disagree. Until you can explain that, there's really no reason to investigate further, don't you think?
Note: the rest of my Non-Belief series is here.