it's unbelievable that the argument of the creationist guy was: "it's not true cause you didn't observe it" and "the evidence it's god's word" as god was someth

it's unbelievable that the argument of the creationist guy was: "it's not true cause you didn't observe it" and "the evidence it's god's word" as god was something we can all observe... how can you discuss on this nonsense?