Please … show me something that is permanent 

It isn’t that something permanent does exist (though that is highly unlikely because if it does exist it has been hiding pretty well) but that it hasn’t shown itself whatsoever. 
Some say the proof is God but nobody has made visual identification of him. There have been no “last seen at …” but just talk. It is all talk. “In the beginning was the Word. And the Word was with God. And the Word is God,” someone named John wrote. But isn’t this just a clever (read: wilful) metaphor?
No, there will never be any way for us to prove that God doesn’t exist. But neither do they have a way to prove that he does (and a capital ‘H’ for He isn’t proof, but only again a choice on the part of the writer.