It seems that he believes that since science cannot prove the existence of God then that must mean there is no God. That or he believes since God has no revealed Himself to him there can be no God. The flaw in his logic is obvious to everyone but him. Czernobog is practicing critical theory which is the the practice of criticizing everything that you don't believe to validate what you do believe. He is confusing critical theory for critical thinking. Critical thinking is criticizing what you do believe to test its validity. He has never done that with his beliefs. If he had he would know that he has no scientific basis for his beliefs. He would know that the scientific principle of falsifiability precludes him from proving something does not exist. In effect, he must take it on faith that God does not exist. Kind of ironic, huh?
It is indeed ironic. Something else that is ironic is how atheists often make the assumption that no physical evidence of a spiritual entity means anything other than a spiritual entity is not physical. This is because, in an atheist's mind, they can't imagine a God (or anything) beyond the physical.
Even the very context of the word "exist" has a different meaning for an atheist. The only "exist" they can comprehend is physical. If it isn't physical, it doesn't exist... ergo, God doesn't exist because God isn't physical.