Bart Ehrman - Jesus Interrupted - The 4 Canonical Gospels in light of one another

I am still concentrating my subject matter on the authority of Bart Ehrman's book - Jesus Interrupted.

This page intends to illustrate the scholarly consensus and a bit of a summary on this historicity, nature, and textual analysis of the gospels.

"Since the nineteenth century, scholars have recognized that Mark was the first Gospel to be written, around 65–70 CE. Both Matthew and Luke, writing fifteen or twenty years later, used Mark as one of their sources for much of their own accounts. That is why almost all of Mark’s stories can be found in Matthew or Luke, and it is also why sometimes all three of these Gospels agree word for word in the way they tell the stories. Sometimes just two agree and the third doesn’t, because occasionally only one of the later Gospels changed Mark. This means that if we have the same story in Mark and Luke, say, and there are differences, these differences exist precisely because Luke has actually modified the words of his source, sometimes deleting words and phrases, sometimes adding material, even entire episodes, and sometimes altering the way a sentence is worded. It is probably safe to assume that if Luke modified what Mark had to say, it was because he wanted to say it differently. Sometimes these differences are just minor changes in wording, but sometimes they affect in highly significant ways the way the entire story is told." 
(Jesus Interrupted - Page 65) 

So according to the scholars,

Mark's Gospel - 65 -70 AD
Matthew and Luke - 80-85 AD
John - 90-100 AD
St Paul's letters - 50-55 AD

Just to illustrate the point further, we take an example of Jesus's death and Bart Ehrman's views.

"When readers then throw both Matthew and John into the mix, they get an even more confused and conflated portrayal of Jesus, imagining wrongly that they have constructed the events as they really happened. To approach the stories in this way is to rob each author of his own integrity as an author and to deprive him of the meaning that he conveys in his story.
This is how readers over the years have come up with the famous "seven last words of the dying Jesus”—by taking what he says at his death in all four Gospels, mixing them together, and imagining that in their combination they now have the full story. This interpretive move does not give the full story. It gives a fifth story, a story that is completely unlike any of the canonical four, a fifth story that in effect rewrites the Gospels, producing a fifth Gospel. This is perfectly fine to do if that’s what you want—it’s a free country, and no one can stop you. But for historical critics, this is not the best way to approach the Gospels.
My overarching point is that the Gospels, and all the books of the Bible, are distinct and should not be read as if they are all saying the same thing. They are decidedly not saying the same thing—even when talking about the same subject (say, Jesus’ death). Mark is different from Luke, and Matthew is different from John, as you can see by doing your own horizontal reading of their respective stories of the crucifixion. The historical approach to the Gospels allows each author’s voice to be heard and refuses to conflate them into some kind of mega-Gospel that flattens the emphases of each one." 
 (Jesus Interrupted - Page 70)