When I tell apologists that many of the stories and concepts in the Bible can be found in pre-Christian/pre-Judaic cultures, the usual mode of defense is something along the lines of: “But my religion has the correct story.”
I can rebut such an argument with the following thought experiment:
- Imagine you walk into Library A and find a book called Story A. Story A was published in 1800 in upper New York. It contains a specific story about a man named Jimmy who is 6 feet tall, has Scoliosis, lives in a blue house on a street named Peach, has 2 dogs and 1 cat, works for a lumber company called Logs Inc., and has a wife named Katherine who is 28 years old.
- You leave Library A and go across town to Library B. You find a book with the title of Story B. Story B was published in 1900 in lower New York. It contains a specific story about a man named Jimmy who is 6 feet tall, has Scoliosis, lives in a blue house on a street named Peachy, has 2 dogs and 1 cat, works for a lumber company called Logs Inc., and has a wife named Katherine who is 29 years old.
- The cores of Story A and Story B are almost entirely alike. However, there are small details which do differ. The small details which differ do not override the rest of the similarities (and the local geographical locations of where the two stories were published is also relevant).
- In the real world of publishing, Story B would be a blatant plagiarized copy of Story A.
- Now replace Story A with the Epic of Gilgamesh and Story B with the Bible, then we can see clearly what apologists are doing when they say their story is the correct version inspired by god.
- They are essentially taking the lower New York copy published in 1900 and saying it’s the original, meanwhile the 1800 upper New York copy was obviously written beforehand. It is a non sequitur: “it does not follow.”
I will present verses I personally selected from Tablet XI of the standard version of the Epic of Gilgamesh (Story A) to show that the Bible (Story B) has a later plagiarized copy of the flood myth. A fact like that makes the later Biblical story obsolete and entirely faulty. Before I cite the verses, I will detail a little history about the culture that composed the Epic of Gilgamesh.
Ancient Mesopotamia gave birth to one of the first civilizations in recorded history, stretching as far back as 5,400 BCE. This is where we find the first form of writing, the earliest Babylonian numerals, the first irrigation systems, and so on. It is the cradle from which the myths and intellectual progress of our species’ infancy was born. 
The Epic of Gilgamesh is a poem that stretches back to roughly 2,100 BCE. Its various versions extended throughout the centuries over a 2,000-year timeline; and it was orally distorted and manipulated by countless generations. The poem is still incomplete to this day because of the diversity of sources and lost fragments, but it’s possible to get a picture of the flood story found in some ancient cuneiform scripts. 
So without further ado, here are my selected verses from the epic:
Lines 8-14: “Ūta-napišti spoke to him, to Gilgamesh: “I will disclose to you, Gilgamesh, a secret matter, and I will tell you a mystery of the gods. The city of Shuruppak — a city you yourself know…that city was old and the gods were inside it, (when) the great gods decided to cause the Deluge.”
Lines 19-34: “Prince Ea was likewise under oath with them, but repeated their words to a reed fence… ‘O man of Shuruppak, son of Ubara-tutu, demolish the house, build a boat! Abandon riches and seek survival! Spurn property and save life! Put on board the boat the seed of all living creatures!’—‘The boat that you are going to build, her dimensions should all be matching: her breadth and length should be the same, cover her with a roof, like the Apsû’.’ I understood and spoke to Ea my master; ‘I hereby concur, my lord, with what you told me thus. I have paid attention; I shall do it.’”
Lines 128-133: “For six days and seven nights, there blew the wind and the Deluge, the gale [and flattened the land]. When the seventh day arrived, the gale relented, [the Deluge and the battle]…the Deluge ended.”
Lines 142-143: “On Mount Nimuš the boat ran aground, Mount Nimuš held the boat fast and did not let it move.” 
The deity told a mortal to build a boat in anticipation of the flood (deluge). The deity details how to build the boat and to put the seed of living creatures on it. From this Story A, came a Story B: the early Judaic tribes inserted their own deity as the maker of the flood, inserted their own characters as the main attractions, and formulated their own personal meaning to a story about genocide.
So there’s our proverbial Story A. Well, I mean, there’s one of them. There are other Story A’s in the same geographical location alongside the epic, I’m merely using Gilgamesh’s as a cornerstone to build off of for this particular analogy; the other Story A’s are in fact testaments to how many times the theme was altered, which then leaves the far later Judeo-Christian version even less exemplary.
This, ladies and gentlemen, is archaic plagiarism at its most rudimentary form. I believe Judaism (along with Christianity) owes the Sumerians a vast amount of royalties—too bad they aren’t around anymore to collect it.
 Dalley, Stephanie. “Myths from Mesopotamia: Creation, the Flood, Gilgamesh, and Others.” Oxford University Press.