Fundamentalists love to quote II Timothy 3:16. In fact one would be justified in observing that this verse is exhibit one in proving that their devotion to the supremacy of Scripture is justified. Unfortunately, this verse does not actually do what they want it to do (demonstrate the truth of Sola Scriptura, that God is the ultimate author of all Scripture, and that the Bible is inerrant).
As has been addressed in past posts on this blog, inspiration suggests the influence of God's Holy Spirit on the human authors of Scripture - that God breathed on them. This does NOT in anyway imply that the human authors of the Bible were merely acting in the capacity of scribes - taking Divine dictation. Rather, it implies that God had a role in what was written down by those human authors. After all, God's Holy Spirit influences, leads, pulls and prompts - it does NOT dictate and control!
But what about the rest of that verse? Let's take a closer look at the actual wording of this very abused scripture. In the King James Version, we read: "All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness." The New International Version renders the same passage: "All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness." Hence, we see that Scripture is useful for (1) formulating teachings/instructions/the precept itself, (2) reproving/rebuking/providing evidence, (3) correcting/improving/restoring righteousness and (4) instructing/educating/training someone to be morally upright. In other words, the author of this passage saw Scripture as a useful tool for a Christian to employ in being a better Christian! (And let's not forget that the only Scriptures available to Christians when this epistle was written were the ones which we now refer to as the Old Testament).
It is also important to take note of what this passage does NOT say. It DOESN'T say that Scripture is a useful tool for explaining scientific phenomena, providing a reliable historical record, serving as the definitive guidebook on human biology or psychology, or functioning as the final authority in everything related to God! The passage DOESN'T state/suggest/imply that Scripture is superior to Science. This passage also DOESN'T state/suggest/imply that Scripture is the only tool available to us for understanding God (If it did, it would be contradicting other scriptures which suggest that studying creation itself is useful in achieving a better understanding of God and "his" purposes.
In other words, so much for this being the primary "prooftext" for Fundamentalists! And, finally, trying to establish the authority of Scripture by quoting those same Scriptures is an exercise in circular reasoning. The real evidence that Scripture has any authority whatsoever is to be found in the experiences of the people who use it - Is it actually helpful with the things listed here and elsewhere in those documents?