For protestants this is a tradition they hold dear. Why is it a tradition? Well because the bible does not say it is the "ONLY" infallible word of God, but rather that "...All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the man of God may be thoroughly equipped for every good work. (2 Timothy 3:15)" This in no way states that Scripture is the only inspired word of God, it just states that it is infallible (God-breathed).
If scripture is the only infallible source, then where in scripture does it state which books belong in scripture? The table of contents is not a part of the bible, so how was the cannon decided? In the 4th and early 5th centuries, the cannon as we have it today in Catholic bibles, was decided upon. In 382 Pope Damasus put together a synod which wrote the Roman Code that identified a list of scriptural books identical to the Council of Trent's formally defined canon in the mid 1500s. In 393 the Council of Hippo reproduced the list. Again the list was reiterated at the First Council of Carthage four years later. In 405 Pope Innocent I wrote a letter to the bishop of Toulouse, which had the same books listed. The list was determined yet again in 419 at the Second Council of Carthage. The new testament was finally closed at the council of Trent, but at this time the protestants threw out 7 books of the old testament, which had been used by the early Christians for 1500 years. The what is the point to all this, Protestants accept two forms of authority outside of scripture, The Roman Catholic Church, and Martin Luther. Luther decided the old testament canon and The Roman Catholic Church decided on the new testament canon.
If protestants accept the Bible as infallible, then they must trust the institution that compiled it to be infallible as well. Is it the Catholic Church that follows traditions of men, or is it Protestants who follow a 500 year old doctrine that scripture alone is infallible, started by a man named Martin Luther? Besides that, before the reformation and even after, only a small portion of Christians could even read, so how could a doctrine that promotes private interpretation ever be true?
Please read these articles also:
http://www.catholic.com/thisrock/1998/9806fea2.asp, "Counting the Canon" KELLMEYER, STEVEN L.
http://www.catholic.com/library/scripture_tradition.asp "Apostolic Tradition (Fathers* ), Can Dogma Develop?, Old Testament Canon (Fathers* ), Proving Inspiration, Scripture and Tradition, What's Your Authority?
Steve Ray masterfully explains sacred tradition and the development of the early Church in these video clips. Please watch and learn about the history of Christianity.
