It is said that all of us have been in the other realms during the beginningless samsara. Since the topic is about devas, I will stick to that realm specifically here.
It is also said that one attains those deva realms, 1: either strictly through the merits of some kamma in the past, in the case of a putthujjana or 2:on having attained the Sakadagami stage. The difference between the two cases is said to be that in the first case only will descent into the lower realms be possible in the future.
Now considering both these facts together it would appear that the ‘inhabitants’ of a deva realm, whether a particular one or in a general sense, will consist of both ‘classes’, riyas and Ariyas existing together, or will they be seperated into regions or sub-spheres, much like humans here are generally born into areas in line with their kamma, the well-to-do living decent lives in civilised countries while others struggle with malnutrition and lack of hygene in Asia and Africa?
Or will those Ariyas in the deva realm be unaware of the distinction (until perhaps until towards the end of that bhava), like those Sotapannas here who are unaware that they are Sotapannas?
y not