Hi well the Bible states that God is the author in which he used certain men, not just any man to write the little books of the Bible, 2 Peter 1:21. Now here is where the authority comes in, all the little books written are throughout time but they all sound alike or rather that seemed to be written by the same person. They must come together and form one large book because that is the goal of God in preparing it in the first place. Many of the little books were hidden together and then found. Later a council was formed with a goal of putting together all the many different books. The council makes sure that all of the books are harmonist and agree together or rather has the fingerprint of God's penmanship.
Another fact about the council is that they were looking for evidence of the Holy Spirit within the pages by the way the words of the little books sound or preached. Now if you have been involved with a church for a long time you will hear about a concept called "the ring of truth". Actually, this is what the council looked for when putting all the little books together, if they heard a "bell" if you will, that sounds off the ring of truth. Under this idea the complete Bible was created, and many books were omitted if they did not have this power radiating from the words of their books, Hebrew 4:12. Once the books come together as sound truth from God, we have basic translation system that is used by comparison to older texts such as Dead Sea Scrolls that validate authenticity. For years we have a complete modern book from God that he created and had completed.
