Oliver Cowdery wrote that the angel Moroni informed Joseph Smith that the prophecy in Isaiah 29:11–14 needed to be fulfilled before the Book of Mormon could be translated, “for thus has God determined to leave men without excuse.”.
The prophecy in Isaiah 29:11-12 says:
11 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, I cannot; for it is sealed:
12 And the book is delivered to him that is not learned, saying, Read this, I pray thee: and he saith, I am not learned.
Martin Harris took some characters from the gold plates to several scholars including Charles Anton and Joseph Smith wrote of this meeting:
We proceeded to copy some of [the characters], and he [Martin Harris] took his journey to the eastern cities and to the learned, saying, “Read this, I pray thee.” And the learned said, “I cannot. But if he would bring the plates, [I] would read it.” But the Lord had forbid it and he returned to me and gave them to me to translate. And I said, “I cannot for I am not learned.” But the Lord had prepared spectacles to read the book. Therefore, I commenced translating the characters and thus the prophecy of Isaiah was fulfilled– History, circa Summer 1832, 5, online at www.josephsmithpapers.org, spelling, punctuation, and grammar standardized.
Why would Joseph Smith introduce this level of complexity if it was all a fraud? Why would he enlist the help of experts if he created the characters himself?