Believe in a God or not, In any age, wouldn't this basic knowledge tell you Earth was round and not flat?
The sun also ariseth, and the sun goeth down, and hasteth to his place where he arose.
Anyone in any age would know the Sun sets in the West and rise in the East, it came not up where it went down, but comes up and goes down in the same places at different ends of the earth.
Would that be enough for anyone to know the Earth was ROUND or a CIRCLE ?
Would you need today's technology to figure that out ?
How about the STARS and the MOON, don't they appear in ROTATIONS even as do the sun ?
With your concept of a disk, then where would be the shadow of darkness cased ?
If it was not round but a disk, then, it would be UNEQUAL hours of Darkness versus Light.
So that argument is not creditable
It doesn't matter, being on Earth, it APPEAR as if the Sun is going down and up, it doesn't suggest that God didn't know Earth is the thing moving....