"Something ONLY exists if there is UNDERSTANDABLE evidence to prove it ? Is that what you claim ?"
Existence is not dependent upon the observer, unless the observer is God or the pope, but in the latter case on things only related to faith.
The matter here is not whether or not something exists, but about upon whom the onus of proving that it does falls upon, and it falls upon the person that makes the statement. If you say that God exists, then give us the proof, until then it is legitimate for everybody else to say: I doubt.
Russell's teapot - Wikipedia