Agnus Dei

The Agnus Dei is a Latin name used to honor the "Lamb of God" within Christian liturgies, including Roman Catholicism, Lutheranism, and Anglicanism. It is a specific prayer that occurs in these liturgies, accompanied by music pieces, and is based on the biblical verse from John 1:29, where St. John the Baptist proclaims Jesus as the "Lamb of God, who takes away the sin of the world!" The title "Lamb of God" has been used in liturgy since Pope Sergius I introduced the Syrian custom of a chant addressed to the Lamb of God in the Roman Rite Mass in the 7th century. In different Christian traditions, the Agnus Dei prayer and music pieces have varying texts and melodies, including in the Church of England's Book of Common Prayer, the Lutheran Service Book of the Lutheran Church–Missouri Synod, and among Evangelical Protestants.learn more on wikipedia