As one who has read the Book of Mormon a number of times, I have noticed that Nephi and Jacob quoted Isaiah pretty freely and made much of his prophecies, but then you don’t hear much about Isaiah again until Abinadi.  And then after that, Isaiah isn’t incorporated again until Christ’s visit to the Nephites when he tells them to study Isaiah.  I have wondered why that is.  I wondered if there was any reason for it besides the ostensible difficulty Nephites had understanding Isaiah’s words.  

I stumbled across a post by Nathan at NR called “Joseph Spencer  on Isaiah, baptism, and theGodhead in the Book of Mormon” that addresses this very issue.  (And there was much excitement and interest in all the land.)

In a later post, Nathan interviews Spenceron Spencer’s article “Prolegomena to Any Future Study of Isaiah in the Book of Mormon.” 

 In these articles, Spencer's theory is presented explaining how the doctrinal focus of Nephi’s use of Isaiah and Abinadi’s use of Isaiah were different and why.   I think you’ll find these things very instructive.