In early Mesopotamian mythology, the world was portrayed as a flat disk floating in the ocean with a hemispherical sky dome above, and this forms the basis for old world maps like those of Anaximander and Hecataeus of Miletus. The recognition that the figure of the Earth is more correctly described as an ellipsoid dates to the 17th century, as described by Isaac Newton in Principia.
But the Bible informs us that the Earth is round almost 2700 years ago. In Isaiah chapter 40 verse 22
Isaiah 40:22: It is he who sits above the circle of the earth, and its inhabitants are like grasshoppers; who stretches out the heavens like a curtain, and spreads them like a tent to dwell in. ESV
The Bible Reveals that the Earth is Round. The word translated circle here is the Hebrew word chuwg, which is also translated circuit or compass. That is, it indicates something spherical, rounded, or arched, not something that is flat or square.
For those who say that in greek philosophers spherical Earth concept was there even around 300-500 BC, for them the reply is that first of all Isaiah wrote this almost in 8th century BC, this is at least 400 years before Aristotle suggested, in his book On the Heavens, that the Earth might be a sphere, and secondly even in greek philosophers the idea was not well established, only on individuals level and not widely spread and accepted. Even in the 15th century AD, it was the Bible that inspired Christopher Columbus to sail around the world. Below are the excerpts from his diary, see what he wrote:
At a very early age, I began to sail upon the ocean. For more than forty years, I have sailed everywhere that people go. I prayed to the most merciful Lord about my heart’s great desire, and He gave me the spirit and the intelligence for the task: seafaring, astronomy, geometry, arithmetic, skill in drafting spherical maps and placing correctly the cities, rivers, mountains, and ports. I also studied cosmology, history, chronology and philosophy.
It was the Lord who put into my mind (I could feel His hand upon me) the fact that it would be possible to sail from there to the Indies. All who heard of my project rejected it with laughter, ridiculing me. There is no question that the inspiration was from the Holy Spirit, because he comforted me with rays of marvelous illumination from the Holy Scriptures … encouraging me to continually to press forward and without ceasing for a moment they now encourage me make haste.
Our Lord Jesus desired to perform a very obvious miracle in the voyage to the Indies, to comfort me and the whole people of God. I spent seven years in the royal court, discussing the matter with many persons of great reputation and wisdom in all the arts; and in the end they concluded that it was all foolishness, so they gave it up. …