Origin of the Bible

The following questions about the origin of the Bible are answered below:
What is the origin of the Bible?
Why weren't the gospels written immediately after Jesus' ascension?
How accurate was the original Bible?
When was the original Bible completed?
Why weren't other writings included in the original Bible?
Why were so many epistles of Paul included in the original Bible?
How do we know today's Bible accurately represents the original Bible?
What is Koine Greek and why was the New Testament written in it?
How does the Old Testament differ from the Jewish Tanakh?

What is the origin of the Bible?

The starting point for investigating the origin of the Bible is The Acts of the Apostles (“Acts”), which is a methodical account of the early Christian church written by a medical doctor named Luke, who served as the assistant to and the note taker for the Apostle Paul.

In 64 AD, the Roman Emperor Nero burned Rome and blamed Christians for the fire to launch his persecution of the early church. In 70 AD, the Roman army sacked Jerusalem. Neither of these cataclysmic milestones in the early church history are mentioned in Acts, which ends with the Apostle Paul completing his 2-year imprisonment in Rome in 62 AD. Therefore, Acts most likely was completed in 62 or 63 AD.

Luke begins Acts with, “The former account I made, O Theophilus, of all that Jesus began both to do and teach...” (Acts 1:1)

The “former account” that Luke refers to is what we now call the Gospel of Luke, which was also dedicated to this man named Theophilus: “Since many have taken in hand to set in order an account of the things that have been fulfilled among us, just as those who from the beginning were eyewitnesses and servants of the word delivered them to us, it seemed good to me also, having carefully investigated everything from the beginning, to write to you an orderly account, most excellent Theophilus, that you may know the certainty of the things about which you have been instructed.” (Luke 1:1-4)

The delivered eyewitness accounts Luke mentions above are what we now call the Gospel of Matthew, written by one of Jesus' twelve Apostles, and the Gospel of Mark, written by the assistant to and the note taker for the Apostle Peter. If we estimate a 3-5 year gap between Acts and the Gospel of Luke and another 3-5 year gap between the Gospel of Luke and the gospels of Matthew and Mark, three of the four gospels were written around 52-59 AD, or only about 20 to 30 years after they last saw Jesus.

Some of the other New Testament books were written before and some after these gospels, but all were written by eyewitnesses of Jesus or their note takers, and read by people who were also eyewitnesses and could validate their details.

Why weren't the gospels written right after Jesus' ascension?

Communication was predominantly oral back then. Things tended to be written down when the speakers felt they won't be able to speak about the content for much longer, toward the end of their lives.

Wouldn't inaccuracies creep into their memory after 20-30 years?

Not in this case, for four reasons:

1.  Today's digital society overloads the human mind with unprecedented amount of information but is relatively tolerant of inaccuracies in our memory because reliable digital copies of the information exist elsewhere on paper, in smart phones, computers, servers, etc. By contrast, the oral society of the antiquity didn't deluge the human memory with such information overload but was also intolerant of inaccuracies in the information retained. Modern digital society's lax demands on the accuracy of human memory shouldn't be applied to antiquity's oral society.

2.  The gospels didn't record the Apostles' recollection of things that happened 20 to 30 years earlier and then hadn't been revisited until 20 to 30 years later. The gospels recorded what they had been talking about everyday during those 20 to 30 years. The recorded content wasn't 20 to 30 years old; it had been refreshed daily for 20 to 30 years.

3.  The events recorded weren't mundane everyday affairs. They were astounding miracles and incidents that defined history. Imagine you had been next to the U.S. President John F. Kennedy's slow moving limousine when he was assassinated. Even in a digital society, wouldn't you clearly remember what you witnessed even 20 to 30 years later?

4.  The people who listened to the Apostles during those 20 to 30 years and read the gospels after they were written included many who also had witnessed the spoken and written content, and they confirmed the accuracy of what the Apostles said, wrote and had dictated to their note takers.