it's not faith if you base it on reason and evidance. i have yet to see a single piece of evidance for God's existance. nor is there any self conistant logical argument that leads to him existing.
what action could a person take other than a confession of his beliefs that would convince you he belives in God?
there is no way to read a person's mind yet., so we have no way of knowing whether he belives or not.
maybe he goes to church out of some obligation to the community, maybe he prays not to a god but to his doctor or lawyer, maybe he just wants attention, or the oppsiite, doesn't want to be an outsider.
I
does god create the rules? if so then how do you know whether or not god has changed his mind recently and has ordered people to kill?
or do the rules exist prior to God? if so then what do you need god for?