Those who have read my series on Biblical inspiration know that I took issue with the use of 2 Tim. 3:16 as a prooftext for the inerrancy of the entire Biblical canon. I stand by my objection, but I have to do a correction nonetheless.
One of my suggestions in my prior post, was that perhaps 1 Tim 3:14-17 should be read as a single sentence, with verses 16 and 17 as a dependent clause on 14 and 15--that is, that the "all scripture" Paul is describing in verse 16 is merely an elaboration on "the sacred writings, which are able to make you wise for salvation through faith in Christ Jesus" in verse 15.
Well, I put that very question to the translators at the NET Bible, as I have read from several sources that they are scrupulously careful with the grammar and the text, even if the result is an unfamiliar reading. Here is their response, authored by someone named "mburer" (I'd give fuller credit if I could, but I don't know how...at least you can follow the link):
It is almost impossible for v. 16 to be a dependent clause. (1) Verse 16 is marked by asyndeton, and this is most normal for independent clauses. (2) Verse 16 has no marks of normal dependent clauses; there is no participle, infinitive, or subordinating conjunction to indicate dependency. (3) If it were dependent and meant to modify τὰ ἱερὰ γράμματα in some fashion, πᾶσα γραφὴ would need to be accusative case as the original phrase is, but it is nominative. (4) The fact that the copulative verb is missing from v. 16 does not argue for v. 16 being dependent. When a verb is lacking in Greek, usually the indicative is implied, which would in fact make this independent. To make v. 16 a dependent clause the participle would need to be implied, and likely Paul would have written that in ful to make the sense clear if that were the case.
Now, I freely admit that the grammatical technicalities they gave here are way over my head. I have submitted this to one other Greek scholar I know who has told me that it's correct, however, so I must accept that my limited knowledge of Greek led me to an incorrect conclusion regarding the division of the sentence. I was wrong to suggest that 14-17 is a single sentence.
However, I still suspect it's a single thought, for the simple reason that the "pasa graphe" that Paul is referring to in verse 16 cannot truly mean "all writing." While it is true that "graphe" as a noun occurs in the New Testament as referring only to sacred writings, the fact remains that the word itself just means "something written down." In fact, according to lexicographers Liddell and Scott, no lesser sources than Herodotus and Plato use the same word to refer to drawing and painting, not to mention plenty of non-sacred written words including catalogues, archives, medical prescriptions, and legal writs. So Paul was using a generic word "writing" not a holy word "Scripture" in verse 16. He cannot have meant that "all writings" are inspired by God, so it remains likely that he's referring to the very writings he just mentioned in verse 14, simply because of context. As I have said before, to apply the statement in verse 16 to the entire canon of our modern, Protestant (or Catholic) Bible is only possible if you start with the presupposition that Paul was foreshadowing a canon he did not yet know about, when he wrote those words. In other words, it proves nothing you have not predisposed it to prove.
However, that's only the phrase "pasa graphe." We have not touched "theopneustos," the word translated "inspired of God" in the KJV, "breathed out by God" in ESV, "God-breathed" in NIV, and "God's breath" in the Pioneers' New Testament. It's a word that didn't get much play at all in Greek literature prior to Paul (if you have the energy for a long and convoluted analysis of the word, have a look at B.B. Warfield's article here). It's broken down, of course into the constituent words "theos" or god (not necessarily always God the Father of Jesus), and "pneustos" which comes from "pneuma" and/or "pnoe," two alternate forms of a word that can mean "spirit," "breath," and "wind" (I hope it's not too insulting, but according to Liddell-Scott, "pneuma"--the same word used of the Holy Spirit, has also been used in Greek literature to refer to flatulence!).
It's certainly appropriate, based on the wide variety of usages of the pneuma/pnoe pair, to understand "theopneustos" as "God's breath." But we have to remember, when we do, that there is an element of "spirit" in the word as well. As such, Paul may be saying as much about the influence of the Holy Spirit in tandem with the content of the written word, as he's saying about the text itself.
The bottom line, however, is that grammar or no, to use 2 Tim 3:16, standing on its own, as proof that the Biblical canon is inerrant, is to lift a sentence out of context, impose rigid meanings on words with much broader history, and basically create a circular proof-loop where the evidence depends upon the conclusion that in turn is being supported by the evidence. That makes no sense.