This more or less happened on Xena. (Obviously, spoilers follow. Although I haven't seen the last ten episodes...) Throughout the series, which is set in Ancient Greece, Xena and Gabrielle constantly reassert that they don't worship any gods or think anybody should, but believe in the works people do. This is influenced by the fact that they actually know and have relationships with many gods (of multiple pantheons - let's not go into the horrors that happen in India), so they know firsthand those gods' many flaws. And um, then there's that whole storyline where Xena goes to war with the gods and most of them die. Which is interesting, but also happens as a way to pave way for the "God of Eli" aka Yahweh. It is quite discomfiting to watch that God be treated as the good and beneficient antidote to the chaos of the Greek pantheon -- but then some doubt as to his goodness is introduced and Xena maintains her "acknowledge all, worship none" stance. I think the real moral of the story is "don't try to make theological sense of XWP" but I did enjoy her longtime reliance on humanity.