Untestable hypotheses

Here is a question, hypothetically speaking: If there is an hypothesis that's untestable, can we even say that it has any effect on the material world, at all? And if the thing we hypothesize has no effect on the world, then can it even be considered relevant or important?

With respect to skepticism and being a skeptic, I look a phenomena and ask "what's the evidence?" Is the hypothesis of the Loch Ness monster testable? Is the idea of ghosts and other paranormal stuff a reasonable one? Do fairies exist? Yeah? What's the evidence?

I also agree that the more extraordinary the claim, the more extraordinary the evidence required to substantiate it. So here's my final question: If the hypothesis of an active, caring god cannot be tested--for any reason--then how can anyone say this god has an influence? Because, if this being influences this world, then we ought to be able to measure it. Otherwise, why do we make these kinds of statements about it? What's our evidence? How do we know?

Saying "you just know" points to things going on inside your mind, and while they're real enough to you, just don't quite rise to the level of reality. Usually we say if something "is only in your mind" and not a reality, we're referring to it as a delusion of some sort; i.e., not real.

I'm not saying; I'm just saying. As a skeptic, I simply cannot give the notion of god a free pass.