A quote from Michael Dowd's book Thank God for Evolution!:
A distinction must be made...between flat-earth faith and evolutionary faith...What I mean by flat-earth faith is not people believing the world is flat. Rather, it refers to any perspective in which the metaphors and theology still in use came into being at a time when peoples really did believe the world was flat--that is, when there was no reliable way for humans to comprehend the world around them by means of science-based public revelation. Religious traditions that are scripturally based, and whose texts have not changed substantially since the time of Copernicus, Galileo, Newton, Darwin, Einstein, Hubble, Crick, Dawkins, and Hawking become, necessarily, flat-earth faiths when interpreted literally....Flat-earth faith makes the mistake of viewing past revelation as a fixed, immutable, and absolutely true and irrevocable message from God that is good for all time. Nothing could be farther from my understanding of what takes place. Past revelation reflects the Weltenschauung of the times. People with a three-tier cosmology invent mythologies to match that cosmology--such as in having Jesus ascend to heaven, whereas, as John Spong points out, with our modern cosmology we know that even at the speed of light Jesus would still be speeding through space 2000 years later and he would not even have left our Galaxy.
"Flat-earth" also characterizes literal understandings of commentaries on sacred scriptures that also predate (or ignore) the evolving cosmological perspective that is the fruit of modern science....Perhaps the most prominent flat-earth commentary in the Christian tradition is the Nicene Creed ("We believe in one God, the Father, the Almighty, maker of heaven and earth, of all that is , seen and unseen...").
Because the Nicene Creed is an interpretation of the core message of the early Christian scriptures, its flat-earth metaphors require modern Christians to speak as if they accept a literal translation of the Bible, although in their minds they may be making the requisite translations. Some liberal Christians bristle at the prospect of having to recite "We believe" for something that they do not in fact believe. Thus in many ways, today's continuing use of flat-earth commentaries to interpret flat-earth scriptures is the most problematic of all. Other Christian commentaries that often contain flat-earth components include papal encyclicals and thousands of sermons delivered every Sunday from pulpits throughout the world. (pp. 64-65)
Flat-earth theology is stuck in a rut. It does not accommodate itself to continuing developments in the understanding of the world and the universe. Religious faith cannot help but be informed by the culture and world-view that produces it. That cannot help but be the case. 2000-year-old writings reflect the cosmology of 2000 years ago. But time marches on.