The church has always taught that
the Book of Mormon is historically true.
If religion works for you and doesn’t harm others, I have no problem with it, even if your belief might be "irrational." However, some who learn more facts about their religion have their faith severely shaken.
"Everything I’d been taught, everything I’d been proud to preach about and witness about just crumbled under my feet. It was such a terrible psychological and nearly physical disturbance."
From an article by Laurie Goodstein in The New York Times:
In the small but cohesive Mormon community where he grew up, Hans Mattsson was a solid believer and a pillar of the church. He followed his father and grandfather into church leadership and finally became an "area authority" overseeing the Church of Jesus Christ of Latter-day Saints throughout Europe.
When fellow believers in Sweden first began coming to him with information from the Internet that contradicted the church’s history and teachings, he dismissed it as "anti-Mormon propaganda," the whisperings of Lucifer. He asked his superiors for help in responding to the members’ doubts, and when they seemed to only sidestep the questions, Mr. Mattsson began his own investigation.
But when he discovered credible evidence that the church’s founder, Joseph Smith, was a polygamist and that the Book of Mormon and other scriptures were rife with historical anomalies, Mr. Mattsson said he felt that the foundation on which he had built his life began to crumble.
Read the article: Some Mormons Search the Web and Find Doubt, The New York Times>>