Why was Jerusalem considered the center of the world in biblical times?
Jerusalem was considered the center of the world because it sits geographically in the center of the planet. At the time of Christ, it was the center of the then-known world, with the Roman Empire extending west to Great Britain, east to India, and including North Africa and Egypt.
The context explains that the Middle East, or Jerusalem, sits pretty much geographically in the center of the whole planet. But at the time of Christ, it was the center of the then-known world. The Roman Empire went west as far as Great Britain, east as far as India, and involved North Africa and Egypt. From that high vantage point, both spiritual beings and Christ in His physical person could envision all the great empires that had ever existed back through history, and possibly even into the future.