For people who believe a supernatural being created the Earth and the rest of the Universe, then they are up for believing literally anything.
Funny though that the ancient Greeks knew the Earth was round, and even had a good stab at measuring its diameter. The "Flat Earth Society" was invented in the Victorian age as a satirical stab at luddites who didn't like the new age. Then history got rewritten, so now people think they are smarter than the ancients, even though some people are clearly MORE stupid than people who lived 2000 years ago. Sad.