Actually, it is quite possible to not believe in gods, talking about D&D. If the deity itself doesn’t show in the mortal world and act only through its followers…
One could simply say that all those miracles are just… magic. Another form of magic. Basically, they stopped being Black Mages and become White Mages. “Never saw a fireball before? And you think it’s some ‘superior being’ taking care of everything.”
Or…
Some people already mentioned the Athar: “All just powerful guys wanting your servitude. Move on, stop being explored.”
Or…
One could believe the gods only exist because of mortals’ faith. Basically, the gods are not real, just an effect of faith. “Stop worshipping them and nothing will happen.”
Or…
Well, I could go on and on, but the point is: to believe in something that is not real is as easy to not believe in something that is real.
Now, there is the considerably easier solution, which is the character not worshipping any gods, despite knowing their existence, for some reason.
But yeah, in this case, the DM decides what happens to the character. But, apparently, one doesn’t need to solve anything: the player already wants a new character, so there’s no problem, in my opinion, of course.
One could simply say that all those miracles are just… magic. Another form of magic. Basically, they stopped being Black Mages and become White Mages. “Never saw a fireball before? And you think it’s some ‘superior being’ taking care of everything.”
Or…
Some people already mentioned the Athar: “All just powerful guys wanting your servitude. Move on, stop being explored.”
Or…
One could believe the gods only exist because of mortals’ faith. Basically, the gods are not real, just an effect of faith. “Stop worshipping them and nothing will happen.”
Or…
Well, I could go on and on, but the point is: to believe in something that is not real is as easy to not believe in something that is real.
Now, there is the considerably easier solution, which is the character not worshipping any gods, despite knowing their existence, for some reason.
But yeah, in this case, the DM decides what happens to the character. But, apparently, one doesn’t need to solve anything: the player already wants a new character, so there’s no problem, in my opinion, of course.