What is scripture?

over the last few weeks, some things have come up through conversations. they have made themselves more and more evident as i've had more conversations about them. i know this could be a dangerous subject and i'm trying not to be a heretic.

the first thing is scripture. what is it, really? my definition is: the word of God, period. so, is ALL of the Bible (as we know it) God-breathed? the easy answer is "yes." i'm not sure if the easy answer is the right one though. i mean, our definition of scripture is different from Paul's. when he said "All Scripture is inspired by God and profitable for teaching, for reproof, for correction, for training in righteousness"...surely he wasn't referring to his letters to Corinth, Philippi, Ephesus, Colossae, et al. Paul was writing letters to his friends, his disciples, his "children in the faith." Do you think when Paul authored a letter to Timothy, it occurred to him that we'd be reading his words nearly 2000 years later? i doubt that. Paul's letters were not designed to become scripture when he wrote them...or were they? in the Bible, when scripture is quoted or paraphrased, it's always Old Testament stuff. when scripture is referred to in the New Testament, it's not Peter talking about something Luke said...it's not John referring to James. did Peter quote Paul's letters when he was preaching? if the Bible, as we know it today (66 books), IS all scripture, why is that so? what about "lost" gospels, epistles, and historical texts that were once considered scriptural? (that is NOT including the so-called gospels that are in direct contradiction to the rest of the Bible) take the book of Enoch, for example. Jude (14-15) quotes it. Enoch was widely accepted in Jesus' time, but in the 300's AD, it was rejected...except by the Coptics. why do Catholics accept the Apocrypha, but we protestants largely ignore those books?

there are a number of references in Paul's letters that indicate a good deal of epistles that we do not have now. a first letter to Corinth (1Cor 5:9), a 3rd epistle to Corinth (2 Cor 2:4 & 7:8-9), an early epistle to Ephesus (Eph 3:3-4), & an epistle to Leodicea (Col 4:16) are all mentioned, but why aren't they in the canon? ....and that's just the Pauline writings.

there is an impressive list of non-canonical books that are quoted, or referred to, in both Old & New Testaments. ( http://en.wikipedia.org/wiki/Non-canonical_books_referenced_in_the_Bible ) if those books were important enough to be widely read & accepted at one point, why were they later rejected?

frankly, it comes down to a matter of faith to me. if i believe God is who He says He is, then He is powerful enough to provide me with a means to know Him and His words.

are those 66 books a complete collection of scripture? probably not, in my opinion.
are those 66 books a sufficient means to have a servicible knowledge and understanding of God? yes.