Because people can not believe that God Called a modern day prophet to expound upon his teachings that he gave to the Israelites or the people of the New Testament. I personally believe that God,who loves us, wouldn't leave us alone without any guidance in such perilous times.
The LDS church is one of the fastest growing churches in the world. It has been perceived as a threat to other churches, and to the livelihoods of their clergy. The majority of the members of the LDS church were not baptized into the church as children, but converted from other faiths. The church is made up of former Catholics, Methodists, Lutherans, Presbyterians, Baptists, and others. The message of the LDS, that people should investigate the Book of Mormon, and pray for confirmation has led to this phenomenal growth in membership. When people receive the confirmation of the Holy Spirit, they gain a testimony that endures. The preachers of the other faiths have responded by spreading lies, rumors, characterizations,NSnd false testimonies concerning the LDS church.
"As an Evangelical I must confess that I am ashamed of our record in relating to the Mormon community. . . . By bearing false witness against our LDS neighbors, we evangelicals as have often sinned not just against Mormons, but against the God who calls us to be truth-tellers."
Richard Mouw, President, Fuller Theological Seminary
The New Mormon Challenge: responding to the latest defenses of a fast-growing movement / Francis J. Beckwith, Carl Mosser, Paul Owen, general eds. (Grand Rapids, Mich.: Zondervan, 2002), p. 11.
Because it has ridiculous stories like a man building a boat out in the middle of nowhere and then a storm that comes and floods the entire earth, or of three men that were thrown into a fiery furnace and survive without a burn, or of a man who actually divides an entire sea and leads millions of people down the middle of it on dry ground, or of... huh?.... what?... say that again?
Those are biblical stories?!?!?! Oh, well then the Book of Mormon ought to be a piece of cake!
Well, we had 290,000 converts in the past year, and some preachers don't like that, so they go out of their way to speak bad about us to keep their congregation (cough.... money) from leaving.
It questions that basic assumptions that other Christian religions are based upon. It causes a person to question the fundamentals of what they believe. This leads people to fear the Lds as they are afraid to lose everything they have based there being on.
Because they are fueled by mass hysteria about things they don't understand. If anyone will actually read the book with an open mind and put it to the test as outlined in Moroni 10:3-5, they will know not to belittle the book or the accomplishments of Joseph Smith in bringing it forth.