The story of the Nephite General named Moroni comes from the ancient text known as the Book of Mormon. If you want to read the stories yourself, you can get a free copy here: https://www.mormon.org/free-book-of-mormon
FAIR USE NOTICE: This video may contain copyrighted material. Such material is made available for educational purposes only. This constitutes a ‘fair use’ of any such copyrighted material as provided for in Title 17 U.S.C. section 106A-117 of the U.S. Copyright Law.