Note, please see the follow-on to this discussion linked at the end of this article.
"All scripture is inspired by God and is useful for teaching, for reproof, for correction, and for training in righteousness. . ." (NRSV). Doesn't this verse conclusively state that our Bible comes straight from God?
Well, not exactly.
First of all we have to look at the word "Scripture." While in modern English that word has the meaning of "sacred writing," the Latin word "scriptura" is much more pedestrian--it just means the written word. In addition to the religious word "scripture," we also get our words "scribe" and "script" from the same root. Similarly the Greek word "graphe" used in the original text is a pretty generic word. You're reading my "graphe" right now, but at least it has some spiritual content. If my wife puts a note on my dashboard reminding me to pick up milk on the way home from work, that's "graphe," too. I doubt the grocery list is inspired by God!
Now it's true that in the first century a lot fewer people were literate. Added to the fact that pens and paper were a whole lot rarer and more costly, and writing back then was likely reserved (mostly) for more significant stuff than the grocery lists, but we have plenty of examples of "graphe" from Paul's time that were most certainly not holy!
But the real key to this passage leaped out at me when I first read it in the old American Standard Version from 1901. Though it's not the most readable version I've ever seen, the 1901 ASV is regarded by many scholars as possibly the most literal translation ever, of the Bible into English. Here is the same verse from the ASV:
Every scripture inspired of God [is] also profitable for teaching, for reproof, for correction, for instruction which is in righteousness.
Notice the difference? That little verb "is" got moved three positions to the right, and it completely changes the character of the sentence. Instead of declaring that "every scripture comes from God," the ASV tells us the somewhat-obvious fact that "anything that comes from God is profitable." The ASV's translation is equally valid because the verb "is" doesn't appear in the original text at all, in either place. A literal translation of the Greek text is more like ". . .every (or "all") writing God-breathed and profitable. . ." Both the translators of the ASV and other English translations inserted the "is" because the sentence doesn't make much sense in English without it. But with apologies to Bill Clinton, where the "is" is, makes a huge difference in the meaning!
The more I think about it and look at this passage, though, the more I suspect that both sets of translators got it wrong. Their error (besides "already knowing what it means" before examining the text) was assuming that verse 16 and 17 are a single sentence separate from verses 14 and 15 before them (and forgetting that Paul is legendary for run-on sentences). If, instead, verse 16 is a dependent clause in the same sentence as 14, we don't need an "is" at all to understand it. Consider this alternate reading of the passage (picking up in verse 15):
". . .from childhood you have known the holy writings (which have the power of wisdom to produce faith in Christ Jesus): every writing inspired by God and useful for teaching. . ." etc.
In other words, the writings which Paul is saying have the power of wisdom to produce faith are those writings which (1) are inspired by God, and (2) are therefore profitable for teaching and all the rest of it. That is, Paul is using the fact that a given writing is God-breathed (as opposed to all th other writing "out there"), as a point of qualification for it's being used for teaching the believer. Stated plainly, "If God inspired it, then it's worth using for teaching." Put that way, it's kind of a no-brainer, don't you think?
To use this passage as it has been used for centuries, as a divine imprimatur over a Biblical canon that did not exist for another 200-plus years is nonsense. I have been told before that "God intended to inspire the canonical council to put all these books together as His word, and so inspired Paul to state that's what they were." This is circular reasoning. . .saying that "the Bible is the Word of God, therefore it says it is the Word of God" only makes sense if you start with the assumption that it's the inspired, inerrant word of God. Paul in this passage said no such thing.
For a correction based on better grammatical analysis, please see this follow-on article.