One of the skeptic’s favorite arguments against Christianity is their claim that much of the Bible is based on old pagan myths. They claim that the Bible is merely the collection, and adaptation, of these myths by Christians. These skeptics say that, far from being the written Word of God, the Bible is simply a retelling of ancient superstitions and legends. They claim that the Christian message, as well as other biblical material, is merely a myth which was co-opted from one of the many religions floating around at the time.
The goal of these skeptics is clear; if the Bible can be proved to simply be a collection of myths, legends, and fables, the God of the Bible is simply a figment of human imagination. This make-believe god would not deserve to be listened to, much less worshiped and obeyed. Therefore, humanity could do as they please, make their own rules, and calm their guilt with the theory that the only god who exists is one of our own imagination.
Do these unbelievers have a point?
Noah and Gilgamesh
In the Old Testament, the Bible gives the account of a man named Noah  [seems there is a movie, loosely based on the story of Noah, that has gotten a lot of attention of late], and his family, who survived God’s judgment of the entire population of earth. This judgment came in the form of a massive flood that would destroy, “…man and animals and creeping things and birds of the heavens…” (Genesis 6:7 ESV, see also Genesis 7:21-23). The Bible treats this flood as a fact (I Chronicles 1:4). Prophets spoke of Noah (Isaiah 54:9; Ezekiel 14:14, 20). The writer of Hebrews spoke of Noah as a historical figure (Hebrews 11:7). Even the Lord Jesus Christ, who was certainly not mistaken, considered Noah to be a real figure of biblical history (Matthew 24:37, 38; Luke 3:36, 17:26, 27).
Nevertheless, the aforementioned skeptics claim that the biblical account of Noah is simply a retelling of the legend of Gilgamesh. They say that this legend is older, possibly dating back to the third millennium B.C., than the Bible’s record of Noah and therefore the Bible must have simply retold the Gilgamesh tale. Atheists point to this writing as proof positive that the Genesis account in the Bible is merely one of many fabricated stories, or fables, in the Bible.
Jesus and Mithra
Atheists also attempt to use the alleged similarities between Christianity and the myth of the god Mithra to say that Christianity is a false belief. They claim that Christianity is merely a religion based on the age old Persian religion of Mithraism. They claim that the Christian beliefs about Jesus are actually taken from the myth of Mithraism and are really pointing to the god Mithra.
However; although the Persian version of Mithraism had its origin around 1400 BC, that version of Mithraism does not remotely resemble the story of Jesus. It is the Roman version of Mithraism that has even the slightest similarities with the life of Jesus. Nevertheless; the Roman version of Mithraism did not appear until the first or second century AD…well after the time of Jesus and the founding of His church. The time-line simply does not allow for the idea that the accounts of Jesus’ life were simply based on the Mithras legend, to be true.
The fact that there are similarities in these accounts should not surprise us. Consider this: if the Genesis Flood  and the life of Jesus really happened as the Bible records, then stories and rumors would be circulating like crazy through a world that transmitted much of its information by word of mouth. Those who rejected the true accounts of Jesus would simply construct false stories which would contain bits of truth. Steve Ham writes, “We would expect to find common accounts of history (such as the creation and the Flood) within the stories and traditions of today’s people groups that once lived together in one place after the great Flood. Given years of cultural diversity as mankind spread throughout the world, it is also not surprising that these stories have taken on their own cultural influences in the retelling” (Ham, p. 60).
Those close to Jesus would know the true story, but those who ignored the truth, would only be hearing part of it. This would leave them to fill in the blanks using their imaginations. History has shown us that we are very good at constructing gods that approve of our own lusts and desires.
While we cannot prove that the biblical account is the true record of history in all its details, skeptics cannot prove otherwise. Nevertheless, the facts are explained better by the idea that the Bible contains the truth and contradicting stories are merely distortions of that truth. The Bible tells us that we are all descendant from the same people, Noah’s family, therefore the account of Noah would naturally be in our collective memories and backgrounds.
However, those who rejected God and His ways, fell away from the Godly line of humanity. It was through this Godly line of people that God preserved the truth, whether written down or by oral transmission. Regardless, it makes much more sense to understand the Bible’s account of the Flood as true and competing accounts as derivations of that record.
The same is true concerning the comparison of the mythical Mithra and the biblical account of Jesus. The Roman religion of Mithraism, the version that contains any similarities at all to the life of Jesus, appeared after Jesus lived and died; therefore, it is impossible for the biblical account of Jesus’ life to have been constructed from the pagan religion of Mithraism.
Jesus really lived and really did what the Bible says He did; He provides the only true way to forgiveness and a relationship with God. It is my prayer that more people will search the Bible, find out who Jesus really is  and what He is like, believe in Him and be forgiven of their sins. God’s Holy Spirit is a powerful witness to the truth of the Bible. This witness will convince one of the truth of God’s Word, give one the ability to live for God, and protect one from false ideas, such as myths, legends, and fables that would lead one away from God. Remember, God began writing the history of humanity on day one of Creation, long before any other competing stories existed.
Related reading: How Do We Know the Bible is True? 
Resources – Ham, Steve. “Is Genesis a Derivation from Ancient Myths?” in How Do We Know the Bible is True? General Editors: Ken Ham and Bodie Hodge. Master Books, 2011.