Just because secularism isn't completely rational and logical positivism doesn't always lead to correct answers 100% of the time doesn't mean that it isn't a BETTER way of determining what is true or false in our physical reality than mere guesswork, a 2000 year old text and someone's say-so.
"Extraordinary claims require extraordinary evidence" - it is not atheism's job to disprove god, it is theism's job to prove god, except they can't, and actually science has disproven most religion's gods categorically so...