Yet there are problems with this challenge. First of all, the test is skewed. A person who “prays” but doesn’t get the same answer as the missionary is viewed as not getting it correct. If prayer is the correct means of testing the book’s authenticity, why is a negative outcome immediately rejected as a plausible response? . . .However, Jeremiah 17:9 says a feeling that one has can be disastrously wrong because “the heart is desperately wicked.” Praying about a religious book, especially if it is fictional and not historical, is hardly an objective test.
If the Book of Mormon is just one of four LDS scriptures, why should it be prayed over and not the other three scriptures? For that matter, why shouldn’t a seeker after truth pray about the Qu’ran (Islam), the Vedas (Hinduism), or the Tripitaka (Buddhism)? Where does praying about a particular religion’s scripture stop? If praying about a book is a way to determine truth, then why have many Mormons never even thought about expanding their prayers to more than just one religion’s scripture?"
Bill McKeever and Eric Johnson, Mormonism 101, p. 135