The Euangelion in Isaiah and Isaiah in the New Testament

Second only to the Book of Psalms, Isaiah is quoted "no fewer than sixty-six times in the New Testament" (Webb) with many more transparent allusions throughout the gospels and epistles.  Of course, the climax of the New Testament in Revelation, the declaration of death conquered, of tears wiped away, of the new heavens and earth, are all drawn from language found in Isaiah.

In the LXX, the words for "good tidings" in 40:9 give us the first use of the word "gospel" - euangelion.  For this and many other reasons, Isaiah is often referred to as "the Gospel according to Isaiah."