When I was growing up, the brand name Kleenex was used by almost everyone to refer to facial tissue regardless of the actual brand of facial tissue. I suspect this may have had something to do with them not having much competition back then. I imagined that the use of their name to refer to all facial tissue must have been a good thing for the Kleenex brand. When someone went to the grocery store, they may have been more likely to buy the box of facial tissue that said "Kleenex" on the box because of the added familiarity they'd have with the name. It is hard to imagine a company being able to accomplish anything quite like that through mere advertising.
When I hear Christians refer to their preferred god as "God," I am reminded of Kleenex. If their god has a name, it seems that most of them are unaware of it or prefer not to use it. Or perhaps they don't use it because they don't have to, thanks in large part to Christian privilege. In many parts of the United States, one could easily spend one's entire life never meeting another person who was something other than Christian or Jewish. Someone living there would hear a great deal about "God" and might never be asked which god they were referring to. But if such a person were to travel, the question might come up. Not everyone they met would have the same point of reference. After all, humans believe in many gods, and some of them even have names. Pointing this out is one of the many ways atheists and other non-Christians can help to undermine Christian privilege.
The curious thing about Kleenex is that even though I still find myself referring to facial tissue as Kleenex, I can't remember the last time I bought a box with "Kleenex" on the label. It has probably been at least 20 years since I've done so. I've always bought (and still buy) the store brand because it is cheaper and I can't imagine that there's enough of a difference to be worth the added expense. As for "God," I recognize that the one Christians prefer isn't any different from any of the others that have been worshipped through the ages. It might be slightly better than some and slightly worse than others, but it has no more evidence to support its existence. That makes it equally unlikely.
Here in the United States, the Christian god is a lot like Kleenex. Many people reflexively use "God" in place of "the god in which Christians and Jews believe" or more appropriately "the god in which I believe." Non-Christians do not make this mistake, and atheists should not make it either. Statements about "God" should always be followed with questions designed to clarify which god the speaker is referring to. This helps the speaker understand that other religions exist and that their preferred god is equally implausible as the gods from the other religions in which they do not believe.
