Nephi wrote, speaking of the messages of the Book of Mormon, "If ye shall believe in Christ ye will believe in these words, for they are the words of Christ...And if they are not the words of Christ, judge ye--for Christ will show unto you, with power and great glory, that they are his words, at the last day; and you and I shall stand face to face before his bar; and ye shall know that I have been commanded of him to write these things" (2 Nephi 33:10-11).
These verses always struck some fear into my heart while on my mission. Not the afraid kind of fear, but an awe and respect for those who've aided in the Restoration of the Church of Jesus Christ, including the authors of the Book of Mormon. Anyone who truly believes in Jesus Christ will believe in the Book of Mormon, recognizing that it testifies of him. Many times, people mock my beliefs and fight to disprove the teachings I've received. I've come to see that it isn't the Book of Mormon on trial, but we will be judged according to how well we lived its precepts...we are on trial.
"And I exhort you to remember these things; for the time speedily cometh that ye shall know that I lie not, for ye shall see me at the bar of God; and the Lord God will say unto you: Did I not declare my words unto you, which were written by this man, like as one crying from the dead, yea, even as one speaking out of the dust?" (Moroni 10:27.)
I know that the Book of Mormon is true. And more importantly, I read the Book of Mormon daily. Knowing it's true is a one-time event...coming to understand and live the doctrine of Christ, as taught in the scriptures, is a lifelong commitment.