Isaiah 29:11 states, " and the vision of all is become unto you as the words of a book that is sealed , which men deliver to one that is learned , saying, read this, I pray thee:and he saith, it is sealed: and the book is delivered to him that is not learned, saying read this I pray thee: and he saith, I am not learned."
Joseph Smith was given power of God at age of 21to translate golden plates of writings which later became published as the Book of Mormon.
2 Nephi 33:10 states " and if ye shall believe in Christ ye will believe in these words, for they are the words of Christ,...and they teach all men that they should do good."
Moroni 10:4 states, " and when ye shall receive these things, I would exhort you that ye would ask God, the Eternal Father, in the name of Christ, if these things are not true; and if ye shall ask with a sincere heart, with real intent, having faith in Christ, he will manifest the truth of it unto you, by the power of the Holy Ghost."