In my view, the Apostle Paul's words are preserved for me to read and heed. Cardinal Newman's words in no way approach the status of Paul's...words that Peter affirms as God-breathed scripture.
My point, however, is not to convince you of my position. My point is to offer an explanation for why I elevate scripture to the position that I do.
I consider it the word of the Apostles.
I hope that you can see that my position is not careless, but is thoughtful and desirous of nothing more than to be faithful to my King.
How do you KNOW? Paul himself warns his congregations at several different times to beware of false writings attributed to him. How do you know that what we have is Paul's writings?
The reason, of course, is that we trust the Church who has handed it down to us. Otherwise, how do you go about disproving such nutty claims that the Da Vinci Code is more correct? In the end, we call the Scriptures the Word of God because we believe that the Church has preserved just that - God's Word.
Regards