Are the epistles of the New Testament the word of God?

The Apostle Paul said, "All Scripture is inspired by God and is profitable for teaching, for rebuking, for correcting, for training in righteousness, so that the man of God may be complete, equipped for every good work." (2 Tim 3:16-17 HCSB) Now, I am aware of the canonization of the New Testament. This was done some 300 plus years after these letters were written. Now, some of these letters do contain scripture references in them but to call them the word of God. I don't think that was the intent of the writers. Why do scholars today say that the whole Bible is the word of God?