The Protestants have defiled and mutilated the book they have idolized, because what they profess as adhesion to the Sacred Scriptures is ultimately an impious egocentricity that deludes them into thinking they as individuals each constitute the magisterium of Christ's Church.
It was the One, Holy, Catholic and Apostolic Church who defined the Canon of the Books of the Bible, availing herself of the divine authority given her by Our Lord Jesus Christ, Who founded His Church upon the Apostles under the primacy and magisterial infallibility of St. Peter and his successors, the Roman Pontiffs:
1) The Council of Hippo (A.D. 393, confirmed in the Council of Carthage, A.D. 397) gave a the list of the Canonical Books of the Bible which was identical to that which was formally defined by the Council of Trent. There is considerate substantiation that before this Council, the Council of Nice formally published the same list of the Canonical Books of the Sacred Scriptures.
2) In A.D. 401, in answer to Exuperius, Bishop of Toulouse, Pope Innocent I gave the exactly the same list as that given by the Council of Carthage. It has been claimed that a similar Canon was given by Pope Damasus (366-384), Pope Gelasius (492-496), or Pope Hormisdas (514-523)
3) St. Augustine in De Doctrina Christiana, II., viii., 13, gives the same list of Canonical Book (wherein lumps the Books of Baruch and Lamentations with the Prophecy of Jeremias).
4) The Council of Florence (A.D. 1438) gives the same exact Canon in the Bull of Pope Eugenius IV Cantate Domino.
5) The Council of Trent definitively defined the Canon of Sacred Scripture against the Protestant heretics in its fourth session, and declared the Vulgate of St. Jerome to be the authentic version of the Holy Bible for the Church.
The above information was taken from The Catholic Student's "Aids" to the Bible by Rev. Fr. Hugh Pope, O.P., (Vol. I, ch. ii.; London: R. & T. Washbourne, Ltd., 1918).