"Why do non-Christians demand so much "falsifiable evidence"?"
Then why, as a Christian, do you demand a computer and the Internet to connect it to? PROTIP: The Scientific Method is precisely the reason why you have the equipment and the facilities to spew your fundie bullshit.
"They want us to test our God through experiment to see if He is real or not."
Enquiring minds need to know. And if proving the existence of such impirically, that means under strict laboratory conditions [/JREF], then so be it. It's the only possible way we Atheists will accept the existence of the nebulous, nonexistent, invisible sky pixie you lot refer to as 'God'.
"Falsifiability is Satanic when applied to God"
Because if it were possible, it would destroy your precious 'faith' and 'belief'. Proof denies 'faith', and without 'faith' there can be no 'belief'. Thus religion is destroyed.
"because He is true no matter what anyone does"
'What's true, is true for you'
-L. Ron Hubbard, founder of $cientology
"and you had better accept that as the Truth."
'Truth' = Subjective. Facts = Objective. Your 'truth' = LIES. Facts can never be disputed. 2+2=4, and all that jazz.
"He exists"
Two Words that are the basis of my Atheism, and completely destroy your 'beliefs' (thus reinforcing my Atheism):
Prove it.