I am not saying that “we have no idea what the authors of the New Testament wrote.” I’ve never said that. The book doesn’t say that. The book is not attacking the Bible and it is not a wild claim that we have no clues about what Jesus and his followers and the later writers of the New Testament thought and said. We do indeed have clues. In most cases we have pretty good ideas.
So why does it matter, “for the bigger picture,” if scribes changed their manuscripts? Because it is one way out of many to show that the Bible people read and randomly cite by cherry picking verses here and there is not a perfect book handed to us by God. In other words, it is one opening among many that was/is meant to take people down the path of critical inquiry into the Bible, to show that you can’t blindly “follow” the Bible.
And once you start taking that path, if you are sincere and honest and truth-seeking – there is no turning back. Only after you start going down it do you start to realize that there are other even more significant problems with the Bible. Only when you look into these other problems do you start to realize that in fact it has contradictions, all over the map; and historical mistakes; and geographical errors; and legends; and myths. You start to realize that we don’t have eyewitness accounts of the life and teachings of Jesus’ (let alone of Moses’!) life and that the accounts we are at odds with each other. And that our sources for Jesus are decades after the fact and are not always reliable.
— Dr. Bart Ehrman, Misquoting Misquoting Jesus, April 26, 2020