In a (hypothetical) atheist country, would belief in God be diagnosed as delusional disorder?

well i dont think so because even in our society today there are peopel with sort of unconventional beliefs, like in certain out landish types of magic or reincarnation and they do not get diagnosed with a disorder right? but if the person engaged in maniacal unstable behavior due to the belief, it woudl probably be diagnosed as a disorder. as it should be