I do believe the word to be infallible. But what I'm saying is that the few times the appearance of the Earth is mentioned in scripture it is unclear. The bible doesn't have to tell us that the sky is blue or that grass is green, because we have been given means to observe these things on our own. And I think that the earth not being flat is demonstrably true.
Modern or ancient, every culture operates within a certain cosmology or understanding of the universe. This cosmology sets the context of how a people understand their world and their place in it. With very few exceptions our modern day cosmology is shaped by the scientific discoveries of the past 500 years. Some of these discoveries have greatly upset religious understandings and it sometimes takes centuries to reconcile the differences. However, since we live in a culture that has been greatly shaped by the bible and Christian beliefs, it is worthwhile to ask about biblical cosmology.
The biblical understanding of the universe is much the same as that of the surrounding cultures in the ancient Middle East at the time when it was written. Unfortunately, nowhere does the bible attempt to present a comprehensive cosmology, so we are forced to rely upon individual passages and to attempt to understand them in the light of their culture and their history. To begin with, biblical cosmology can be characterized as a three-tiered universe. This strange phrase needs some explanation to make the concept clearer.
First, the surface of the earth is circular and flat except for geographical features like hills and valleys. This of course was the belief of the Sumerians. To these people it was theoretically possible to go high enough to see the entire earth, or to envision a tree tall enough that it could be seen from everywhere on the earth's surface, or even to build a tower to reach the sky. The sky was thought of as a solid bowl, called the firmament, that was upended over the circular earth to enclose a volume in the shape of a hemisphere. I should add that there are some bible verses that speak of the four corners of the earth. This was the view of the Babylonians. This would make the firmament look more like a tent than a bowl. The lights of the sky (sun, moon, planets and stars) were inside the firmament and were very much smaller than we presently understand. In fact they were very much smaller than the earth itself. The mechanism by which these celestial objects moved about is not really explained. The noncanonical Book of Enoch (mentioned in the bible as authoritive and part of the canon of Ethiopian Christians) speaks of gates in the east and west for the sun and the moon to enter and leave. Enoch also suggests that their movements are caused by winds.
What I have just described is the middle tier of the three. Above the firmament are waters. This region is described as heaven, the abode of God and the angels. There were also gates in the firmament to permit water to enter as rain. Below the earth are also waters. This region is described as sheol or hell. There were also gates in the earth to permit water to spring up from below. This three level universe is variously described as either hung on nothing or supported by pillars. Storehouses are also envisioned in heaven for the snow and hail.
How should a of Christian today react to this biblical cosmology? The vast majority of what might be described as 'mainline' Christians are actually quite comfortable with this seeming dichotomy. They recognize that the bible is the product of a relatively unsophisticated people with an entirely pre-scientific understanding of nature, who used poetic or metaphorical language to convey their spiritual understandings. On the other hand there is the minority point of view of those Christians who regard the bible to be inerrant and to be understood literally. This group has been forced into extreme apologetic efforts in order to reconcile the bible with modern scientific understandings.
Speaking personally, I find these apologetic attempts to be rather inventive and very strained. I believe that if the scripture writers and early target audience were to read these apologetics, they would find them extremely puzzling and entirely foreign. This is not to say that they were not intelligent people or not keen observers of nature but rather that that they lacked the intellectual basis to form scientific hypotheses and even the instrumentation to gather accurate data --- all that came about some 2,000 years later.
Isaiah 11:12And he shall set up an ensign for the nations, and shall assemble the outcasts of Israel, and gather together the dispersed of Judah from the FOUR CORNERS OF THE EARTH. (KJV)
Revelation 7:1And after these things I saw four angels standing on FOUR CORNERS OF THE EARTH, holding the four winds of the earth, that the wind should not blow on the earth, nor on the sea, nor on any tree. (KJV)
Job 38:13 That it might take hold of the ENDS OF THE EARTH, that the wicked might be shaken out of it? (KJV)
Jeremiah 16:19 O LORD, my strength, and my fortress, and my refuge in the day of affliction, the Gentiles shall come unto thee from the ENDS OF THE EARTH, and shall say, Surely our fathers have inherited lies, vanity, and things wherein there is no profit. (KJV)
Daniel 4:11 The tree grew, and was strong, and the height thereof reached unto heaven, and the sight thereof to the ENDS OF ALL THE EARTH: (KJV)
Matthew 4:8 Again, the devil taketh him up into an exceeding high mountain, and sheweth him all the kingdoms of the world, and the glory of them; (KJV)
Psalms 104:5 "He set the earth on its foundations; it can never be moved."(NIV)
Psalms 93:1"The LORD reigns, he is robed in majesty; the LORD is robed in majesty and is armed with strength. The world is firmly established; it cannot be moved." (NIV)
Psalms 96:10 "Say among the nations, "The LORD reigns." The world is firmly established, it cannot be moved; he will judge the peoples with equity." (NIV)
Ecclesiastes 1:5 "The sun rises and the sun sets, and hurries back to where it rises." (NIV)
Isaiah 40:22 "He sits enthroned above the circle of the earth, and its people are like grasshoppers. He stretches out the heavens like a canopy, and spreads them out like a tent to live in." (NIV)
Job 9:6 He shakes the earth from its place and makes its pillars tremble. (NIV)
Job 26:11 The pillars of the heavens quake, aghast at his rebuke. (NIV)
Job 38:22 "Have you entered the storehouses of the snow or seen the storehouses of the hail," (NIV)
Amos 9:6 The One who builds His upper chambers in the heavens and has founded His VAULTED DOME over the earth, He who calls for the waters of the sea and pours them out on the face of the earth, The LORD is His name. (NASB)
The biblical flat earth cosmology persisted into New Testament times. However by the mid second century Christianity had largely lost its Jewish roots and understandings and had become a gentile Greek speaking movement. Of course the Greeks knew that the earth was a sphere thanks to Eratosthenes who actually was able to calculate the circumference around 240 BC. This knowledge gradually percolated into Jewish and Christian thought especially after Ptolemy introduced his cosmology in the mid second century. The earth became the center of the universe with the moon and then the sun and then the planets, with complicated epicycles, and then the “fixed” stars all in orbit around it. This was the cosmology accepted by Christianity until the revolution of Copernicus, Kepler. Galileo and Newton. This was resisted by Christianity largely on the basis that the earth was not the center of God’s creation. In a relatively short time even this scientific insight was not only accepted but accepted to the extent that the biblical cosmology of a flat earth was rejected. The flat earth was not only rejected but ridiculous arguments were even invented to suggest that the bible was not even suggesting a flat earth at all. Such, all too often, is the way some Christians react to new understandings and insights.
Even having said all this, the belief in a flat earth persisted for a very long time, even in educated circles, as is evidenced in this comment by Ferdinand Magellan, the first person to circumnavigate the globe: “The church says the earth is flat, but I know that it is round, for I have seen the shadow on the moon, and I have more faith in a shadow than in the church.” It took time but the modern cosmology took root in society at large, so much so that some Christians even return to the bible and attempt to reinterpret it in such a way as to “prove” that it was speaking of a spherical earth orbiting the sun all along.
