This straw man argument is typical of many attempts of cult liberalism and other cults to say that there are errors in the Bible.  The Bible talks about the circle (literally sphere) of the earth.  It says that this sphere is hung on nothing at all.

But it also speaks of the four corners of the earth, a figure of speech still used today that is not used to indicate a flat earth.  Actually the four corners is not a literal translation from the original Biblical language.  The literal interpretation is more like four directions . . . like North, South, East, and West.

Intellectuals have repeatedly had some fun trying to attach this flat-earth label on Christians.  It is a tactic that is emotionally childish and very typical of the ungodly.

"Without a doubt, Earth is round, or nearly so. Using careful measurements from the ground and observations from space we can be certain it is essentially a sphere, with only minor bulging near the equator. If reduced to the size of a billiard ball, it would be perfectly smooth, and we wouldn't even be able to feel the highest mountains or deepest oceans."
Read more at: http://www.icr.org/index.php?module=articles&action=view&ID=2703

Given the fact that an earth the size of a billiard ball would be perfectly smooth so we would not even be able to feel the highest mountains or deepest oceans, it makes us realize the foolishness of the claims made by such cults as atheism regarding the flood.  These cults tend to claim that there is no way that water could have covered the whole earth during the flood.  They'll ask such naive questions as, "Where did all the water go then?"  The Bible says that, after the flood, the ocean floors dropped and the mountains arose.  Their assertion that the water could not have covered the mountains is almost a "flat earth" type of claim.  You drop those mountains a little bit and raise the oceans a little bit and you have a total flood.  Not only that, but they never thought through the reality that a flood could never remain on a flat earth.  Even a child would realize that.

AnswersInGenesis.org

Christianity has often been held responsible for promoting the flat Earth theory. Yet it was only a handful of so-called intellectual scholars throughout the centuries, claiming to represent the Church, who held to a flat Earth. Most of these were ignored by the Church, yet somehow their writings made it into early history books as being the official Christian viewpoint?.

AnswersInGenesis.org

One person, who was trying to prove that there must be one error in the Bible, was grasping at a Bible verse to show, at least in his mind, that the Bible does teach that the earth is flat.  Well, he insisted that you had to make certain assumptions and accept his personal rendering to the meaning of certain words.  His basic assumption is that his own mind is superior to God's, who wrote the Bible.  God states very clearly that no prophecy of the Scripture is of any private interpretation and that the natural man cannot receive the things of the Spirit.  This poor mans useless mind was casting about for some sort of a way out of the fact that the Bible is without any errors.  Thinking himself wise, he proved that he is a fool.