Once again, the Bible is not a scientific journal. Of course the authors of the Bible believed that the earth was flat. That was the prevailing scientific view. Look at
The Flat Earth..
"The Bible is, from Genesis to Revelation, a flat-earth book. ...While the Bible nowhere states categorically that the earth is flat, numerous Old Testament verses clearly show that the ancient Hebrews were flat-earthers.
That the earth was considered essentially flat is clear from Daniel, who said, "I saw a tree of great height at the centre of the earth; the tree grew and became strong, reaching with its top to the sky and visible to the earth's farthest bounds." (
Daniel 4:10-11) Only on a flat earth could one see a tree reaching the sky (dome?) from "the earth's farthest bounds."
The New Testament also implies a flat earth. For instance,
Matthew 4:8 says that "The devil took him [Jesus] to a very high mountain, and showed him all the kingdoms of the world in their glory." From a sufficiently high mountain, one could see all of the kingdoms of the world “but only if the earth were flat. The same applies to
Revelation 1:7, which says that at the second coming, "Every eye shall see him." Finally,
Revelation 7:1 refers to "the four corners of the earth," and corners are not generally associated with spheres.
The Biblical cosmos model derives from Egyptian sources, which had a flat earth covered by a rounded sky vault supported at the four corners of the earth by high mountains. The 'waters above and the waters below' in the book of Genesis refer to the Babylonian notion that the waters were divided, and some remained above the sky vault. The vault was like a leaky roof and some of that water falls down as rain.