According to McConkie and Millet, a primary purpose of the Book of Mormon is to convince the world that the testimony and teachings of the Bible are true. In 2 Nephi 3:11 we find the following:
But a seer will I raise up out of the fruit of thy loins; and unto him will I give power to bring forth my word unto the seed of thy loins--and not to the bringing forth my word only, saith the Lord, but to the convincing them of my word, which shall have already gone forth among them.
Will Durant in his volume Caesar and Christ makes the following comment as his introduction to a consideration of the historicity of Christ and the Gospels:
One of the most far-reaching activities of the modern mind has been the "Higher Criticism" of the Bible--the mountainous attack upon its authenticity and veracity, countered by the heroic attempt to save the historical foundations of Christian faith; the results may in time prove as revolutionary as Christianity itself. The first engagement in this two-hundred-year war was fought in silence by Hermann Reimarus, professor of Oriental languages at Hamburg: on his death in 1768 he left, cautiously unpublished, a 1400-page manuscript on the life of Christ. Six years later Gotthold Lessing, over the protests of his friends, published portions of it as the Wolfenbuttel Fragments. Reimarus argued that Jesus can only be regarded and understood not as the founder of Christianity, but as the final and dominant figure in the mystical eschatology of the Jews--i.e., Christ thought not of establishing a new religion, but of preparing men for the imminent destruction of the world, and God's Last Judgment of all souls. In 1796 Herder pointed out the apparently irreconcilable difference between the Christ of Matthew, Mark, and Luke, and the Christ of the Gospel of St. John. In 1828 Heinrich Paulus, summarizing the life of Christ in 1192 pages, proposed a rationalistic interpretation of the miracles--i.e., accepted their occurrence but ascribed them to natural causes and powers. In an epoch-marking Life of Jesus (1835-36) David Strauss rejected this compromise; the supernatural elements in the Gospels, he thought, should be classed as myths, and the actual career of Christ must be reconstructed without using these elements in any form. Strauss's massive volumes made Biblical criticism the storm center of German thought for a generation. In the same year Ferdinand Christian Baur attacked the Epistles of Paul, rejecting as unauthentic all but those to the Galatians, Corinthians, and Romans. In 1840 Bruno Bauer began a series of passionately controversial works aiming to show that Jesus was a myth, the personified form of a cult that evolved in the second century from a fusion of Jewish, Greek, and Roman theology. In 1863 Ernest Renan's Life of Jesus, alarming millions with its rationalism and charming millions with its prose, gathered together the results of German criticism, and brought the problem of the Gospels before the entire educated world. The French school reached its climax at the end of the century in the Abbe Loisy, who subjected the New Testament to such rigorous textual analysis that the Catholic church felt compelled to excommunicate him and other "Modernists." Meanwhile the Dutch school of Pierson, Naber, and Matthas carried the movement to its farthest point by laboriously denying the historical reality of Jesus. In Germany Arthur Drews gave this negative conclusion its definitive exposition (1906); and in England W. B. Smith and J. M. Robertson argued to a like denial. The result of two centuries of discussion seemed to be the annihilation of Christ. (Will Durant, Caesar and Christ [New York; Simon and Schuster, 1944], pp. 553-54)
The story of Bible scholarship for the past two or more centuries surely evidences the wisdom of God in bringing forth the Book of Mormon in defense of the testimony of Christ and the message of the Bible.
It is also of some considerable significance that the prophecy explicitly stated that we are to use the Book of Mormon to prove the Bible rather than the Bible to prove the Book of Mormon. [Joseph Fielding McConkie and Robert L. Millet, Doctrinal Commentary on the Book of Mormon, Vol I, pp. 206-207]. [See the commentary on 1 Nephi 13:40]