More than once, back when I was a Christian, I heard preachers remark how consistent the Bible is - how it was written over a period of many years by different people living in different parts of the world, and yet is completely consistent with itself.
The Bible is in fact consistent with itself in some places, but this is not so amazing, since the New Testament writers would have had copies of the Old Testament to refer to. In fact, in Matthew's Gospel, he often records an incident, and then quotes the Old Testament passage that supposedly predicted it.
This is just one of those things that preachers say about the Bible - they'll say that it is full of great wisdom, and it's a guide for living.
This always reminds me of the man who has an eight-year-old son who is a horrible child - does poorly in school - starts fights with other children - but if you ask him about his kid, he'll say, "Oh, little Randy is a charming child, and he's soooooo smart."
You really don't expect a father to tell the complete truth about his eight-year-old kid. Nor should you expect a Christian minister to tell the truth about the Bible.
Biblical consistency? You might want to look at the four Gospels.
I will refer to them as "Matthew," "Mark," "Luke," and "John," even though we don't know the names of the actual authors (it would be extremely cumbersome for me to have to keep saying "the book we refer to as 'Luke' even though we don't know who the true author is").
The first three - Matthew, Mark, and Luke - are called "synoptic" because they are very similar. But each author has a private agenda, and he obviously doesn't think he's bound by any kind of historical truth.
In John's gospel, which was written maybe 40 years after the other three, Jesus repeatedly says "I am." I am the bread of life; I am the way and the truth and the life; I am the gate for the sheep. In the other three Gospels, Jesus just doesn't talk about himself.
Two of the four Gospels - Mark and John - don't even mention the virgin birth.
Matthew's gospel (Matt. 27:52ff) recounts that "many" people came out of their graves (when Jesus was crucified) and were seen by "many."
Many people saw these zombies.
Think about this for just a minute. A mass resurrection. Just like in "Night of the Living Dead."
If this had really happened, the other three Gospel writers would surely have made note of it ... but they didn't. It never happened. Matthew inserted this - he made it up - because he thought it would make the story better.
In fact, there were real live historians (not Christians) living in Jerusalem at this time (Josephus, for instance). Not one of them recorded the mass resurrection.
Sometimes when Matthew reports an incident - an incident that is also recorded in one of the other Synoptic Gospels - you find that Matthew likes to embellish it, a kind of "one-upmanship."
Which brings me to Spiderman.
I was a young child, just starting to read, and I bought my comic books for 12 cents apiece. Stan Lee introduced us to Spiderman in an issue of Amazing Fantasy in 1962 (that issue is now selling for $71,000.00 in good condition).
I remember all the details of Spiderman's backstory - Aunt May, Uncle Ben, the Green Goblin, the Sandman, "Flash" (the school bully). Peter Parker was bitten by a radioactive spider, and somehow this gave him all of his special abilities.
But in the real world, there is no Spiderman. There never was. He is a character of fiction.
1962 was a long time ago, and nobody cares about the purity of the original story.
Spiderman was reintroduced to a new generation in 2002 with a movie - Tobey Maguire playing Peter Parker. The old "origin story" from the comic book (which was 40 years old) was doctored, tweaked, updated. Why not?
After they made a few movies, they casually changed the origin story (again), and in 2012 Andrew Garfield was suppressing his British accent to play the part of Peter Parker, and Aunt May was played by Sally Field. The absence of Peter Parker's parents was explained with new background information.
And after a few of these Andrew Garfield movies are made, suddenly (in 2016) there's yet another Spiderman with a new origin story, and this time the actor really is a teenager (Tom Holland), and his Aunt May is played by Marisa Tomei, and Spiderman is given a special electronic suit by Tony Stark (Iron Man).
Counting the original comic book origin story, this (Tom Holland) is the fourth iteration of Spiderman.
It's the same with Jesus and his four different "origin" stories.
Jesus is a myth.
He is a fictitious character; he is "made up." Matthew felt free to make up stuff about him, including the crazy story about the resurrection of "many" saints around the time of the crucifixion (Matt. 27:52ff).
Matthew wanted to outdo Luke and Mark. And Matthew is obsessed with connecting the (made-up) story of Jesus with stuff that's written in the Old Testament.
John did the same thing in his gospel: he made up a pretty story - it's in the 8th chapter - the story in which Jesus says, "Let him among you who is without sin cast the first stone." It's a great story, and it's featured in every movie that has ever been made about Jesus. It even shows up in Godspell, which is supposedly based on the Gospel according to Matthew (not John).
(I'm not sure that the adulterous woman story shows up in Jesus Christ Superstar).
John's gospel, which was written about 70 years after the events that it describes, contains lengthy verbatim quotes from Jesus (see John 14-17 four chapters which are basically one long dissertation by Jesus).
It is almost certainly true that after the Gospels were written (by the original authors, whose identity is unknown), they were "doctored" by the monks who made the handwritten copies - sometimes to make them correspond with each other a little more closely. The guys who made those handwritten copies didn't seem to mind "correcting" things. Scholars are pretty sure that the ending of Mark's gospel (Mark 16:9-20) - where it "fleshes out" the story of the resurrection of Jesus - was not in the original version.
The story of Jesus is a suffering hero myth, and "truth" (especially historical truth) has little or nothing to do with it.
The point of the Jesus story isn't whether or not it's true; the point is to make a point.
And there's reason to believe that the book of Acts also belongs in the "myth/legend" category.
By the way, fundamentalists who believe (or claim to believe) that every word of the Bible is true will tell you all about the thousands and thousands and thousands of "New Testament manuscripts" that we have. They'll talk about other ancient documents, such as the writings of Marcus Aurelius, or the writings of Homer, and they'll tell you that there are only a few hundred copies of those works.
What they don't tell you is that
Many of those "thousands and thousands" of New Testament manuscripts are just a page or two - something that was found in an ancient garbage dump.
The VAST majority of the "ancient manuscripts" date back to the 1400s and 1500s, and are in Latin.
In most instances where we have more than one manuscript of the same passage, no two of them match - there are thousands and thousands of "textual variations."
A quick note about "textual criticism:"
There are three letters in the New Testament - I Timothy, II Timothy, and Titus - which are attributed to Paul. Scholars are pretty sure that Paul did not write them, that is, that they are forgeries which date to the Second Century CE.
The reasons that scholars believe this are:
1. Paul's other letters - the 20 or so other New Testament "books" which are attributed to him - are addressed to churches, not to individuals (with the exception of Paul's brief letter to Philemon). When there was a problem at a church, or Paul wanted to convey some kind of teaching or doctrine, he wrote to a church, not to an individual.
2. The total vocabulary of these three letters is 848 words. 306 of those words don't appear in any of Paul's other letters. And 2/3 of those 848 words appear in Christian literature of the Second Century.
3. In these three letters, there are instructions about a hierarchy in the church. This kind of hierarchy was unknown in the First Century church, and is not addressed (in any meaningful way) in Paul's other letters.