The Muslims say that we are "People of the Book," but we are not that (only): we are People of the Word.
Because the Word is not only what is written. The Word is first spoken, then performed. Then written.
This is certainly true of the NT, which was spoken and performed for decades, -- parts of it for generations --- before it was written. If you just take the written part, precious though it is, you are missing out on a lot of the Word.
Without the "spoken" word --- the Oral Tradition, the Preached and Practiced Tradition--- we wouldn't even know what the books of the NT Scripture are. We wouldn't even know who wrote the Gospels of Matthew, Mark, Luke, and John, since their names are not listed as authors of these books. No in the manuscripts! We know it only by the other avenues of Sacred Tradition.
And--- inasmuch as the written Scriptures were transmitted, collected and canonized for us by the Fathers of the Church, why would you trust the accuracy of one part of what they handed down to us, and not trust the rest of what they handed down to us?
It was the Oral Tradition that birthed the Written Tradition.
and not trust the rest of what they handed down to us?
Too many years, too many hands and too much unknown. Some of it may be true and other parts less so. God has given us what He wants us to have. I am satisfied what He gives. Blessed be His Name and His Word.