Disclaimer: The link depicted in the image is fictitious, intended for satirical purposes, and at the time this article was published, does not exist. Seek it out at your own risk.
If atheists took the Bible in context, it would be much easier to have a reasonable discussion about it. Take, for example, Balaam's donkey. Every atheist knows this story, because it's one of the most popular objections raised against the Bible. Donkeys, of course, do not talk, so no infallible book is going to claim they do.
However, anyone capable of reading will be able to swiftly dispel this silly argument, because the story neither claims, nor assumes, that donkeys can talk. Instead, Numbers 22:28 specifically says God opened the mouth of the donkey. Both the talking donkey, and the equally common talking snake, (Ezekiel 28:13; Revelation 20:2) were supernatural occurrences performed by extremely powerful, supernatural beings.
So, what does this make this obnoxious atheist slogan? It makes it a straw man argument. A straw man argument is when a debater misrepresents their opponent's position, then proceeds to attack the misrepresentation, appearing to defeat the real position which has not, in reality, been harmed. In this case, atheists misrepresent the Bible, then attack the misrepresentation in an attempt to make Christianity look stupid. In reality, anyone who uses this argument makes themselves look ignorant. No one who uses the talking donkey/talking snake argument has a shred of credibility.