The sentence "Frodo carried the One Ring to Mount Doom" is not literally true, but it is true within the fictional narrative of the Lord of the Rings. You can simultaneously believe it and not believe it, in a certain sense, by applying the so called "suspension of disbelief", a mental mechanism which probably evolved to allow us to consider hypothetical conterfactual beliefs for decision making and which we then started using to make fiction.

I think that theists like Robert Aumann who support the non-overlapping magisteria position are doing something similar: they accept "the world is 15 billion years old" as an epistemic "Bayesian" belief which they use when considering expectations over observations, and they apply suspension of disbelief in order to believe "the world was created by God in six days" in the counterfactual context of religion.