Handel's Messiah has been described by the early-music scholar Richard Luckett as "a commentary on Jesus Christ's Nativity, Passion, Resurrection and Ascension", beginning with God's promises as spoken by the prophets and ending with Christ's glorification in heaven. In contrast with most of Handel's oratorios, the singers in Messiah do not assume dramatic roles; there is no single, dominant narrative voice; and very little use is made of quoted speech. In his libretto, his intention was not to dramatize the life and teachings of Jesus, but to acclaim the "Mystery of Godliness", using a compilation of extracts from the King James Version of the Bible, and from the Psalms included with the Book of Common Prayer.
The three-part structure of the work approximates to that of Handel's three-act operas, with the "parts" subdivided by Jennens into "scenes". Each scene is a collection of individual numbers or "movements" which take the form of recitatives, arias, and choruses. There are two instrumental numbers, the opening Sinfony in the style of a French overture, and the pastoral Pifa, often called the "pastoral symphony", at the mid-point of Part I.
In Part I, the Messiah's coming and the virgin birth are predicted by the Old Testament prophets. The annunciation to the shepherds of the birth of the Christ is represented in the words of Luke's Gospel. Part II covers Christ's passion and his death, his resurrection and ascension, the first spreading of the gospel through the world, and a definitive statement of God's glory summarized in the "Hallelujah". Part III begins with the promise of redemption, followed by a prediction of the day of judgement and the "general resurrection", ending with the final victory over sin and death and the acclamation of Christ.