When Jesus came to the Americas after His death and Resurrection, He quoted from the scriptures, but of the words of Isaiah, he said: “A commandment I give unto you that ye search these things diligently; for great are the words of Isaiah” (3 Nephi 23:1). He also told the Nephites that all that Isaiah had prophesied would be fulfilled (see 3 Nephi 23:3).
The book of Isaiah was written when the Jews were in wickedness and apostasy. Its message covers events of Isaiah’s era and events that would occur in the future, often at the same time, in a layered fashion. However, the most important part of the book is Isaiah’s witness of Jesus is the Christ as the promised Messiah.
Studying the book of Isaiah can strengthen anyone’s testimony of the Savior. Reading carefully will teach you to listen to the Spirit as you come across symbolism in this book. “As students mature in their understanding of the gospel, they can appreciate Isaiah’s witness and feel a desire to study his words and say as Nephi said: ‘My soul delighteth in his words … for he verily saw my Redeemer’” (2 Nephi 11:2).
Excerpts are taken from the “Old Testament Seminary Teacher Manual | Introduction to the Book of Isaiah