A common accusation found in sectarian criticisms about the Church is the idea that Mormons, though claiming to believe in the Bible, do not emphasize it as much as they do the Book of Mormon. This, they say, is evidence that Mormons are not really Christians, but merely give lip service to Christianity by claiming to believe in a book that that they do not even read.

I have previously written about how Mormons are actually the only ones who believe in a perfect Bible, so I won't go into that now. However, I will share a very apropos quote from Heber J. Grant, former prophet and leader of the Lord's Church:

All my life I have been finding additional evidences that the Bible is the Book of books, and that the Book of Mormon is the greatest witness for the truth of the Bible that has ever been published.

The Bible and Book of Mormon are companions engaged in a common cause. If there is a senior companion, though, it is the Bible. The Bible is a more expansive work that encompasses more of our Heavenly Father's plan than the Book of Mormon does in various ways:

1. It gives a detailed account of the Creation. The Book of Mormon gives no such account.
2. It has the story of Abraham and his descendants, which is a central theme in the Book of Mormon, though it is not fully explained there.
   
3. It gives a more detailed account of Christ's ministry on Earth. Four versions of it, actually. We have a similar account in the Book of Mormon (in Third Nephi), but it is significantly shorter.
4. It gives a detailed account of the end of the world in Revelation. Nephi, a prophet who wrote part of the Book of Mormon, saw the same things that John saw, but the Lord forbade him from writing them because that was John's mission.

And yet, anyone who has been contacted by missionaries from the Church of Jesus Christ of Latter-day Saints can tell you that our missionaries push the Book of Mormon before they push the Bible. This is not a contradiction; there are very legitimate reasons for this:

1. People generally have a better understanding of the Bible than the Book of Mormon. They are both works of scripture given by God. If we don't educate people about the Book of Mormon, no one will.
2. While the Bible's general message is fuller than the Book of Mormon's, it has lost some of its purity. Either intentionally or accidentally, translators and transcribers have removed or changed many plain and precious truths that were originally in the Bible. The Book of Mormon, though conveying less information, is more pure in the information that it conveys. (Unless you are reading the Joseph Smith Translation of the Bible.)
3. The Bible testifies of Christ and His doctrines and tells about the Church that Christ established in this world. The Book of Mormon does the same - and stands as evidence that the Church spoken of in the Bible has been restored to the world through modern prophets.

Yes, the Bible is the book of books, but its authenticity has long been a matter of debate. The Book of Mormon stands as a testimony of its authenticity - and as evidence of to whom we may look for an inspired and authoritative interpretation of the Bible's words. The Lord lays out the mission of the Book of Mormon when speaking to the prophet Nephi:

Wherefore, the fruit of thy loins shall write [the Book of Mormon]; and the fruit of the loins of Judah shall write [the Bible]; and that which shall be written by the fruit of thy loins, and also that which shall be written by the fruit of the loins of Judah, shall grow together, unto the confounding of false doctrines and laying down of contentions, and establishing peace among the fruit of thy loins, and bringing them to the knowledge of their fathers in the latter days, and also to the knowledge of my covenants, saith the Lord.

We do, in fact, believe in the Bible. The reason we believe in the Book of Mormon so much is because we believe in the Bible. The Book of Mormon cannot stand without the Bible - and never was meant to.