There are so many hate-filled, anti-Christian comments in this thread by the original poster it is difficult to even begin to take it seriously. I will not bother with refuting hate-filled positions, but I will address an assertion made in the original post:
I understand that some disagree as to whether or not Paul was the first writer but I do believe that most serious scholars, Christians included, agree that Paul was the very first. It is difficult to find a coherent argument to refute this most likely scenario. This being the most likely case, what "scripture" could Paul have been referring to when he said that "all Scripture is “God-breathed.” He said it this way: All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be competent, equipped for every good work." (2 Timothy 3:16-17 ESV)
That quote of yours from the bible is in English, more specifically modern English. No one spoke or wrote English 2000 years ago, in fact no one spoke modern English until about 500-600 years ago, and no one spoke the form of modern English we speak now until about 250 years ago. While it varies based on which part of scripture we are talking about, for much of the New Testament our oldest, best surviving copies of very old versions of the text were written in what modern scholars call Koine Greek. This was a sort of "courtly" Greek, used in business, law, diplomacy throughout the Mediterranean from around 300 BC to 600 AD. It was predominant especially in the Eastern Roman Empire--which is where Christianity's earliest churches arose. Latin, which was used primarily in Rome, in the Western Empire, and by Roman leadership was not really used by the people who were early Christian writers, not until many years later.
In the original Koine Greek, the word used in 2 Timothy 3:16 is "γραφη", that is directly translated from Koine Greek to English as "a writing." The word derives from the Koine Greek verb, "γραφω", which essentially translates as "to scratch." Language evolves and changes over time, from the Greek term for "to scratch", people began to use that as the base for their word for "writings" and etc, essentially people would engrave words on stone tablets and clay tablets, and the act of "scratching" eventually evolved into a noun that meant "written text." The word from 2 Timothy, specifically, γραφη, has an even more particular meaning, it actually
refers to the meaning behind etchings or scratchings. As an example, the word "γραφη" would be used roughly in a sentence like this, "I really liked the γραφη in his essay." That means you liked the meaning of the writing. The other form, γραμμα, you would use in a sentence like this, "I liked the γραμμα in the letter he sent me." That would be saying you were appreciating
the physical marks on the page, i.e. you thought he had good handwriting basically. You can't actually just drop this word in the middle of an English sentence like that, but that's as close as we can get.
Any translator writing an English bible translation has a huge work ahead of them, because you cannot just simply direct translate Koine Greek into English. A direct, word by word translation of 2 Timothy 3:16 from Koine Greek would read this way:
all Classic divinely inspired and profitable toward teaching toward exposure toward - toward lesson the in righteousness
That is literal gibberish in English, because you need to understand cultural context, linguistic context, the dual-meanings and idioms of words as spoken by
Greek speakers 2000 years ago. This isn't the work of Google Translate or BabelFish.
To finally get to the point--Paul was not referring to scripture the way a modern English speaker does, which means Holy Christian scripture in the bible. He was essentially referring to old sacred writings more generically, and then
more specifically, he was actually referring to a long lost book called
The Book of Jannes and Jambres, which you can read more about in various places. It was basically an old Hebrew apocryphal religious text, that still could be found in libraries and such in Paul's time, but which no modern copies survive.