I am a born again Christian and believe in God the Creator, father, Spirit and Son. but i am yes perfectly capable of discussing the possibility that God doesn't exist. Because if he doesn't exist then why would we have a need for laws rules and social and democratic laws rules and authorities. we could all do as we pleased, eat drink and be merry so to speak and to hell with anyone else. why would we need to try be at peace with each other when we are all doomed to just die and that be the end of us.
we would have no need for a intellectual brain. we'd not need to care for others have love grace and mercy. all of these things i get from my God. I and most others would just go wild if we didn't think there was anything more than this life that is here in front of us. it isn't just christians who have thought there is a God. nearly every civilisation has acknowledged that there must be some supernatural God being in existence.