I imagine something like this will be one of the first experiments proposed if Sam Harris ever manages to find a particular area of the brain that is responsible for religious belief:
Words failed me. I stuttered as Prof Vincent Walsh turned off the speech centre of my brain for a few thousandths of a second to demonstrate the power of transcranial magnetic stimulation, a popular way to interfere with the most complex known object in the universe.
Of course, as I suggested to him in an email, if he ever manages to find such a location or brainwave pattern, it would be interesting to test those secular rationalists who think so highly of evolution and determine just what sort of belief they truly have in it.