President Benson, prophet from 1985-1994, teaches us about the importance of the Book of Mormon in our lives.  He teaches that the Book of Mormon is important to us because it is the keystone of our religion, was written for our day, and helps us draw nearer to God.  This talk is where the phrase "Keystone of our religion" originated.  In this talk, listen for ways that the Book of Mormon is the keystone of our religion.

https://www.churchofjesuschrist.org/study/general-conference/1986/10/the-book-of-mormon-keystone-of-our-religion?lang=eng