The longest chapter in the Book of Mormon happens to be one of my favorites. It’s a beautiful telling of the Olive Tree Allegory which is hinted at several times in the Bible, but missing from that text. The Book of Mormon quoting this story helps to offer context not only for this life, but also of the story of the Children of Israel that’s so well documented in the Bible.
When I was in High School The Church of Jesus Christ of Latter-day Saints produced videos to help explain this allegory. One of these got published online. It’s dated, but the message is still good.
Also, if one cares this one chapter has over 600 pages of commentary in a wonderful book titled, The Olive Tree Allegory.