The canticle Dignus est agnus, (Worthy is the Lamb) is taken from Revelation 5:12-13b, 15:3b, 19:5b-6
Worthy is the Lamb who was slain,
to receive power and wealth and wisdom and might
and honor and glory and blessing!
To him who sits on the throne and to the Lamb
be blessing and honor and glory and might
forever and ever!
Great and amazing are your deeds,
O Lord God the Almighty!
Just and true are your ways,
O King of the nations!
Who will not fear, O Lord,
and glorify your name?
For you alone are holy.
Praise our God, all you his servants,
you who fear him, small and great.
Alleluia! For the Lord our God the Almighty reigns.
Alleluia, Alleluia! Amen.
Source: Common Service Book of the Lutheran Church, revised using phrases from The Holy Bible, English Standard Version.
The canticle Dignus est agnus seems to have its origins in American Lutheranism in the late 19th century. It appeared in several service books beginning with the General Synod’s Church Book of 1868.
It appears on p. 122 of The Lutheran Hymnal (1941) without music. Earlier books prescribed its use as an option for the main canticle in Matins and Vespers (in place of the Te Deum or Magnificat). Later books suggested it as an alternative song of praise in the Common Service (in place of the Gloria in Excelsis).
An article on Dignus est agnus by John Warwick Montgomery can be read here: http://www.ctsfw.net/media/pdfs/montgomeryhistoricalstudy.pdf
The text of this canticle has been reworked into a new canticle, This Is the Feast of Victory / Worthy Is Christ, by poet John W. Arthur. It first appeared as an anthem for choir, Festival Canticle: Worthy Is Christ with music by Richard W. Hillert, and made its first appearance in a hymnal in Lutheran Book of Worship as an alternative to the Gloria in Excelsis in the Divine Service.
This is the feast of victory for our God.
Alleluia, Alleluia, Alleluia.
1 Worthy is Christ, the Lamb who was slain,
whose blood set us free to be people of God. [Refrain]
2 Power, riches, wisdom and strength,
and honor, blessing and glory are his. [Refrain]
3 Sing with all the people of God
and join in the hymn of all creation.
4 Blessing, honor, glory and might
be to God and the Lamb forever. Amen. [Refrain]
For the Lamb who was slain
has begun his reign. Alleluia. [Refrain]
© 1978 Lutheran Church in America, The American Lutheran Church, The Evangelical Lutheran Church in Canada, and The Lutheran Church – Missouri Synod
Parts of this canticle are identical with the introit for Christ the King in the Roman rite. This is the Latin text:
Dignus est Agnus, qui occisus est, accipere virtutem, et divinitatem, et sapientiam, et fortitudinem, et honorem.
Ipsi gloria et imperium in saecula saeculorum.
Deus, judicium tuum Regi da: et justitiam tuam Filio Regis.