You're approaching this the wrong way, theists are the claimants who are asserting god exists and they have the burden of proof, theists should be providing a reason to believe it's not the job of the atheist to disprove god.
The best you can do is investigate why a the theist believes and then find the inevitable faulty logic in their thinking and address it.
The best you can do is investigate why a the theist believes and then find the inevitable faulty logic in their thinking and address it.