I bet a lot of them don't even know he has a particular name.
I also think there are a lot of liberal Christians (like ones I know) who think that all of the ideas of "God" and gods throughout history are really all referring to the same god, and so it doesn't really matter which god or gods you believe in.... just so long as you aren't an ATHEIST!
In a way, I agree with these liberal theists. There really is no difference between believing in one god or the other. (Either way you've decided to take fantasy over reality.)
But I guess your point is to get them to realize that there are other gods out there? And then from there, you can ask them why they don't believe in those other gods? (Unless they're the liberal theists I mentioned.)
From time to time, when somebody mentions god, I'll ask them "which one" just for giggles. They have no clue what I mean at first and I get to repeat the question. Then they tell me and I say "Ah, okay then." It really tones down the reverence for whatever point they were about to make.
Do you know that most Christians think that "God" is God's name? I think it's pretty funny. It's like thinking "king" is the king's name. It's a title and, you're right, people need to be more specific which god they're referring to. OH BUT THERE'S ONLY ONE! Ummm, except, if you read the Bible, even "God" commands his followers not to worship "other" gods... thereby acknowledging them and their threat to him being singularly worshiped.
I'd be willing to bet that this question would stump many of the believers (Christians) I know. I'm pretty certain that they think God's name is God)... At the very least, it could knock them off their 'game' a bit.
I once informed my mother that "God" was not God's name. She argued with me. That was irritating. She doesn't even realize that "god" is a generic term to describe deities and the only reason they capitalize the "G" is because they're referring to their own personal god. That's why it's stupid when Christians get all up in arms when people use "God's" name in vain! "Oh my God!" shouldn't be as offensive as someone saying "Oh your god!" My god might be Buddha, after all.
This actually gives me a really good idea. If a Christian ever asks me if I believe in God and I don't think they are very knowledgeable about their religion then I will just say, "Yes, I believe in Yahweh". If they know who Yahweh is then I'll just say "Actually, I'm an atheist I was just seeing if you knew the name of your god."
However, if they start asking me who Yahweh is and asking me why I believe in Yahweh then I will start to provide the "evidence" that a typical Christian would use. Except I will obscure references to the Bible by using lesser known terms for different portions of the Bible (e.g. Torah, Pentateuch, Acts of the Apostles, epistles etc.) Then after going back and forth a little with the Christian, I will eventually say, "Actually, I'm an atheist, but it's really funny that you don't know the name of your own god or the history of your religion."
I just think this would be devastating for a Christian to realize that they were arguing against their own religion and didn't even know it. I don't even know how they would respond at that point. Has anybody else tried this?
Christian: "And I just felt God's powerful presence lifting my spirit..."
Prazzie: "Which god?"
Christian: "Huh? The God of the Bible!"
Prazzie: "Oh? Which Bible?"
Christian: "The King James Bible, of course!"
Prazzie: "Oh, ok. Which version of the King James?"
Christian: "Um, not the New King James Version, the one before that!"
Prazzie: "Ok, so the Authorized King James Version, which edition?"
Christian: "It doesn't matter, it's all the same! God's Holy Bible!"
Prazzie: "Right, so which God in the Adulterous King James Bible of 1631?"