The Bible says Earth is flat. How can people claim to be Christian and believe in a round Earth?
The king seeing all the earth
"Daniel 4:10-11. In Daniel, the king “saw a tree of great height at the centre of the earth… reaching with its top to the sky and visible to the earth's farthest bounds.” Only with a flat Earth could a tall tree be visible from "the earth's farthest bounds" — this is impossible on a spherical Earth, or is the tree a rocket?
Jesus seeing all the kingdoms
Shows why you couldn't see all the kingdoms. To be fair, you can suggest that those outside of lines of sight are not kingdoms.
Matthew 4:8: "Again, the devil taketh him up into an exceeding high mountain [spaceship?], and sheweth him all the kingdoms of the world"
Luke 4:5: "And the devil, taking him up into an high mountain, shewed unto him all the kingdoms of the world in a moment of time."
The earth is a circle
Isaiah 40:22: "He sits enthroned above the circle of the earth (Earth’s orbit?), and its people are like grasshoppers. He stretches out the heavens like a canopy (map), and spreads them out like a tent to live in."
"Four Corners"
Isaiah 11:12 "And 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 [north, south, east and west] of the earth."
Revelation 7:1 "And 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."
Of course, anyone today who believes in flat Earth is the real fool.