Let's take the New Testament first. In spite of what some liberal Bible 'scholars' say, the teaching of the RCC is that Matthew was written no later than 6 years after Jesus' death, resurrection and ascension. It was also written originally in Hebrew. Mark was written 6 years later, in Greek, and Luke and Acts were written about 26 years after Jesus' death, resurrection and ascension.
So all three synoptic gospels had been written by 62 A.D. The Gospel of John was written circa 80 to 85 A.D. and is recognized as the gospel that emphasizes the theology of Christianity. That is why we find specific instances at different points in this gospel; the instances were used to illustrate the theology rather than as purely calendrical events.
Polycarp, Bishop of Smyrna and martyr for our Lord, spoke of the four gospels in a letter he wrote circa 108 A.D. The earliest surviving list we have of the New Testament books which were included in the Council of Nicea's final compilation of books dates to about 170 A.D. It's called The Muratorian Fragment, and you can read its English translation here:
www.bible-researcher.com/muratorian.html
It includes nearly all the books that are in the present-day New Testament plus two that were not included.
As for the Old Testament, it has gotten vindication from science. Dr.Wells, a DNA researcher, has been studying the DNA of Africans, Asians and Aborigines, being financed by grants from IBM and The National Geographic Society. As of the last report, he has found that all these people had one man as their common ancestor. According to the documentary that aired on the NGS channel a few months ago, scientists now believe that
homo sapiens went to the very brink of extinction about 30,000 years ago. The only reason that we are now here is because one man was able to survive whatever wiped out the rest, and the repopulation of the world began with him. They have given him the name 'Adam'.
As for the Creation Story in Genesis, it is not a myth. Rather, it is a demythologization. We must remember that this was written for the edification of the Hebrew nation, a people that had just left Egypt. While there they were witnesses to, and many probably participated in, the festivals which celebrated the pantheon of gods and goddesses. The list includes over 40 different deities that were worshipped, with each one having the form of an animal, the sun, the moon, or the stars. But starting with Genesis 1:1, Moses reduced everything that could be seen to the status of merely material, so that by the time The Creation Story was completed, the only god worthy of worship was the immortal and invisible God.
As for Adam, Eve, God and The Serpent, Moses 'cleaned up' another egyptian myth. In egyptian mythology, Osiris fought Sebau the Serpent. Having conquered him, Osiris hacked off his front legs and bound his back legs together, forcing Sebau to crawl on his belly as punishment. God was able to accomplish the same action merely by willing it, which meant that He was exponentially more powerful than Osiris.
The Great Flood may quite literally have happened. After finding an entire herd of mastodon dead and dismembered at the base of a cliff, scientists did some investigating. The evidence showed that these behemoths had been grazing placidly on the prairie near the cliff when a wind literally picked them up and dashed their bodies against the cliff with sufficient force to dismember them before they fell to the ground at its base.
We have never experienced a wind of this magnitude in recorded history. It was so powerful that our measurements of wind magnitude cannot even measure it. But it happened, and the scientists wanted to know why. Meteorologists, climatologists, mathematicians, paleontologists, oceanographers, and every other conceivable science got together to figure out (1) what happened to cause this, and (2) could it happen again.
What they decided was this: Based on observations and mathematical calculations the tilt of the earth on its axis as it rotates very gradually becomes more angular. This gets to the point that every 26,000 years the planet has a 'seizure', acting much the same as a child's top does just before it falls over. This only lasts a short while before the self-correcting gyroscope that makes up the metal and molten core of the planet brings it back to its original angle of declination. But during the interim the atmosphere and water on the planet react to its gyrations in an extremely violent manner. The article I read stated that it was like filling a glass with water, holding it in your hand, and then shaking your hand back and forth as forcefully as you can.
Some scientists suspect that this is the origin of The Great Flood Story. The power of the wind, the resultant storm surge pushed before it, and the enptying of the sea basins themselves as a result of the massive shaking of the planet would easily wipe out any and all villages near the shore, as well as for miles inland. Since most people lived near shorelines, they would be wiped out before they could even start running.
As for Abraham and his descendants, they were people who really lived between 1700 and 2000 B.C. Archeologists, egyptologists, and many conservative Christians believe that Joseph was sold as a slave to Habiru, another race of semitic peoples who ruled part of Egypt for some time. He rose to prominence with these people, but was relatively unknown as Joseph by the native egyptians. He had been renamed Zaphenath-Penah.
After the conquering of the Habiru by Achmose, pharaohs came to power who either did not know Joseph or else wanted to purge Egypt's records of all actions not performed by their own people. So they enslaved the descendants of Abraham. As a conservative Christian I accept, as do others, that it was during this period of egyptian history, rather than during the reign of Ramesses the Great, that we encounter Moses. We suspect that it was Hatshepsut who found him. She was the daughter of Pharaoh Thutmose II; she was also his main wife, Queen of Egypt, and stepmother of Thutmose III. She had the clout necessary to save Moses, adopt him, and rear him im the palace under the tutelage of the egyptian priests, scribes, and military officers.
Following the death of her father, and husband, Hatshepsut took control of Egypt as a pharaoh rather than as a queen. Thutmose III was 9 years old at that time, and not yet ready to assume the reins of leadership. There does not appear to have been a problem with the court officials, so the transition from queen to pharaoh went smoothly.
It is believed that Moses and Thutmose III both received military training together in the egyptian art of warfare. Josephus writes in his Jewish Antiquities that Moses was one of the generals in pharaoh's army. As such, he had led that army into Ethiopia, where he successfully crushed a revolt. Josephus also writes that Moses was forced to flee Egypt as a result of pharaoh's being concerned that Moses would attempt to take the throne for himself. This fits with Thutmose III's attempt to erase all record of Hatshepsut's having reigned following her death, as well as destroying all records of her accomplishments. This, by proxy, would have included Moses' military exploits.
And where do we put Ramesses the Great? Egyptologists who could actually read heiroglyphics found the written record of his victories on a wall in Egypt. There, in a 'box' carved on the wall, was the record of his having demanded tribute from the King of Israel. Then they read I Kings 14:25, and realized that the Old Testament had not misspelled the name of Pharaoh Shishank when they wrote it down in the original Hebrew. Instead, they had used the Hebrew word 'shishak' to describe the actual pharaoh who conquered their land; it means 'destroyer of cities', an apt pseudonym for Ramesses the Great.
Hope this helps.