As for Columbus – there were many sailors just before his era who were beginning to venture further out on the ocean and make longer trips. They were noticing the curvature of the earth on the horizon and began to theorize that the Bible was wrong about the earth being flat.
Educated persons, Christians and otherwise, all knew the earth was round–this was common knowledge since the ancient Greeks. It is possible, likely even, that flat-earthers existed among sailing folk. The Bible really says nothing definite about the shape of the Earth. This has been a non-starter for most everybody except rationalist-fundamentalists.
Columbus – and other sailors – were testing a theory which was based on evidence. The evidence that the world was probably round could be seen on long sea voyages.
Probably not. The scientific method as such was still to come in Western civilization. The evidence for the round earth was already part of Greek science before Christ.
The people who doubted Columbus were Christians who believed the Bible could not be wrong. Columbus was brave enough to test the theory. But the theory was not based on ‘faith’ – it was based on what appeared to be real evidence that the horizon was a curve.
The people who doubted Columbus were also Christians who thought more for Ptolemy’s findings of the size of the Earth. They had an inkling that Japan and China were much farther west of Europe than Columbus was promoting. The monarchs Ferdinand and Isabella were feeling flush from the Muslim exit from Spain, and they were willing to take a gamble on the Genoan sea captain. Or maybe they were just hoping to be rid of the man.
Like many people of religion, Max brings his own bias to his fervent arguments. It is unfortunate for atheists that so many of them unknowingly promote the bias about dimwitted Christians holding back the tide of truth and science. It’s not that much different from believers who complain about the stupidity of atheists. A Christian or an atheist may well be knowledge or curiosity-challenged. But it’s probably not due to religion or lack thereof.