The context is about the sacred direction of Muslims or the qibla by David A. King:
Frequently over the years other folk have introduced the factor that the Earth is not a sphere into the qibla discussion, which is not helpful.
The Cambridge dictionary defines the meanings of the term 'sphere' as:
1- an object shaped like a round ball.
and
a subject or area of knowledge, work, etc.
So the problem I have is that I can't quite figure out the exact meaning of the term based on the sentence. Does it mean that earth is not considered as a sphere-like shape in the qibla discussion, or, the earth is not considered as one of the subjects included in the qibla discussion? Or maybe even something else?
I know that my question might have a simple answer, but I'm really stuck on this and as a translator (English to another language) I have to know the exact meaning, so I would really appreciate your help.