I think the idea is this: whether something needs a cause or not is not the issue. The issue is whether something can be tested for truth or not. For example, when someone came up with the concept of the Big Bang, they could test some things about it. Despite the fact that we have no observer to say whether a Big Bang happened or not, we can put together some working models as to how it might have occurred and what the results would be. Then we can see if we can find any of these results in our reality. What we discover allows us to valid an idea, negate an idea or to change an idea. But we have things we can test and observe in order to see if there is any validity in the concept.

When it comes to God there is not test. There is no way to prove that he/she/it is out there. Someone can have the idea ... the concept ... but it is simply not testable.

So, when we talk about theories for the universe and how it all came together, we have ideas we can test and ideas we cannot. God is not only an unknown, but not testable. And, on top of that, with all the gods out there, none of them seem to fit with what we have learned about our universe. As such, most scientists would have to conclude that there is either not a god or gods or that, if there is, then we simply don't know who he/she/it is.