Stump the Christian?

[Esquilax]

Did I say that God has never interacted with the material world?  

He created it, and became man, so yeah.

How does science test, measure and verify the immaterial?

What you are describing above are not immaterial claims, they are very definitely material ones, concerning material things and the interaction of your god with materials that we can test.

Besides the blatant category error of your thinking, the other thing is that, once again, you can't shift the burden of proof and then demand everyone else prove you wrong: you have the burden of proof for the flat claim that science cannot test god, and it's one that you're simply ignoring.