Narrator and character. Biographer and subject. Whenever people talk in a written work, there is a difference between how you are supposed to take the words of the author versus the words the author wrote down from various people.
For a quick example, consider the following text:
Suddenly, out of nowhere a large, metallic woman appeared out of nowhere. “It’s my mother!” Dornob exclaimed. Little did he know just how wrong he was.
In this text, two people make statements. The first is the narrator. He is (in most writings) assumed to be correct. The other person saying things is Dornob. He is a character in the story, and unless the narrator tells you that Dornob is infallible or just right, we assume that he is no more or less reliable than the average bear. In this particular case, Dornob is quite wrong, and the narrator tells us so. Of course, the narrator doesn’t have to tell us explicitly that Dornob is wrong for him to be wrong. Past, future, or outside material may make that clear.
This same logic applies to real world writings, too. A reporter can write a piece on the events of the day, but that doesn’t mean he thinks every person he quotes is correct. Sometimes he’ll say so specifically, but other times he may quote something someone said that he knows is not entirely correct without comment, simply because we know he doesn’t agree 100% with everyone he interviews.
To most of you, this probably sounds like common sense (if I’m speaking clearly, that is). But for a lot of people, this basic logic seems to disappear when the Bible is involved. What do I mean? I’ll jump to an example:
His servants asked him, “What did you just do? While the baby was alive, you fasted and wept, but when he died, you got up and ate food.”
He answered, “While the baby was alive, I fasted and wept because I thought, ‘Who knows? The LORD may be gracious to me and let him live.’ But now that he is dead, why should I fast? Can I bring him back again? I’ll go to him, but he will never return to me.”
2 Samuel 12:21-23
Now, this text is in narrative form. The author is telling a (historical) story. So we have to remember that there’s a difference between what the author/narrator says and what the people he is writing abut in the narrative say. The author was divinely inspired, but the the people he wrote about were just people saying what people say. We would probably agree already that the servants didn’t say anything divinely inspired, so what about David? He is just a person in the narrative, and he is not the inspired author/narrator. Therefore we should also read his words as merely his own, not divinely inspired.
Of course, if you recognize this verse, you may see where this is going. Many Christians use verse 23 to argue that infants who die go to “heaven” (something I do believe, by the way). After all, the Bible says that David would go to his baby, right? Completely wrong. The author/narrator under the inspiration of the Spirit does not say that David will go to be with his child. David himself said that, and the author of 2 Samuel just wrote down what David had said. David had just sinned against God big time, and he had just lost his child. There is no special reason to think that he is speaking God’s words here. Seeing his child again was his own expectation, which could be right or wrong. (As a side note, since God had revealed so little about life after death at this point, David probably wasn’t talking about heaven. He probably just meant they would be together in the grave.)
There are other examples of this kind of thing throughout the Bible. For example, David, the same person from before, lied in 1 Samuel 21 (which was written by the same author, probably). The author doesn’t specifically say that David lied, but the story shows he did. In Genesis 30:18, Jacob’s wife Leah says that God has rewarded her for letting Jacob make a baby with her slave girl, and the text never mentions that she was wrong, but we know from the whole of Scripture that polygamy is wrong.
We always, then, have to make a distinction between what the inspired author says himself and what the people he is writing about said. Otherwise, we can be led into any error of the people the Bible talks about. But since we don’t trust everything the Pharisees, the serpent, or lying Jacob said, we must also remember that we can’t trust everything even the good people said when they are just characters in the story, not the author.
Basically, don’t believe what everyone in the Bible says.