A question about 2 Timothy 3:16 from a commenter inspired (pun intended) me to think about the text in a different light.
One possible background for the rare term θεόπνευστος (theopneustos), sometimes rendered as “God-breathed,” is the story in Genesis 2, in which God breathes the breath of life into the human being he has made, and the human being becomes a living soul.
If that is the background, then the analogy is interesting to explore. A human being without the presence of life and breath turns to dust and is mere matter. Could we say the same of the Bible? It is just bones, just words, just dust, just matter. It is God acting and giving life to those words that matters (another intentional pun), and not the words and letters themselves. Without the divine presence, the words become useless, just like a human body when the breath of life is no longer present.
If that is the point, then this text does not support the way it is used by inerrantists, and perhaps undermines their arguments.