The General Instruction of the Roman Missal describes the Gloria as "a most ancient and venerable hymn by which the Church, gathered in the Holy Spirit, glorifies and entreats God the Father and the Lamb."


The Great Doxology

The Gloria was originally written to be a hymn of praise to God so it is referred to sometimes as the Great Doxology. The word Doxology comes from the Greek (doxa - "Glory" and logia - "saying"). The practice of using hymns of praise in the early Church came from their Jewish origins. The "Glory Be to the Father" [Gloria Patri] is sometimes referred to as a doxology or lesser doxology while the Gloria at Mass is considered the Great Doxology.

From Early Christianity

While no one is exactly sure how or when the hymn was created, it seems to be derived from a very ancient Greek hymn of the 3rd and even possibly the 1st century. The beginning of the Gloria echoes the words of the angels in Luke 2:14 at the Nativity of Christ ("Glory to God in the highest and on earth peace to those on whom his favor rests."). As other verses were added over the years it became part of morning prayers by the 4th century

Tradition attributes the Latin translation to Saint Hilary of Poitiers (c. 300-368), who is said to have learned it while in the East (359-360). A book dating from the 4th-5th century called the Apostolic Constitutions contains the Gloria in its entire form. When it gradually was introduced into the Mass, it was only used on special occasions. It made it's first appearance in Mass during the papacy of Pope Symmachus (498-514) but was only used when a bishop presided over the Mass. But by the 11th century it became an established part of all solemn Masses

Today's Gloria contains many references to scripture and it is quite easy to note examples of this, including verses from the Psalms (Psalm 145:2 and Psalm 119:2). It also contains strong similarities to St. Polycarp's final prayer, as recorded by Eusebius, uttered just before he was martyred in 156-167 AD: "I praise Thee for all, I bless Thee, I glorify Thee..."

3rd Edition Roman Missal Gloria

There are significant changes to the 3rd Edition Roman Missal translation of the Gloria. Most of these changes are to bring the current English translation closer to the Latin text which expressed the sentiments of the early Church while relying heavily on Scripture. The phrase "Lamb of God" (John 1:29) remains in the new version and there are references to Christ "taking away the sins of the world", who is "seated at the right hand of the Father" in Romans 8:34, Ephesians 1:20 and Hebrews 1:3.. Now when we say "We adore you, we glorify you , we give you thanks…" ..we continue instead with... "for your GREAT glory". The word 'great' in describing the Glory of the Lord is found throughout Scripture (example Sirach 44:2).

In making the English translation more faithful to the Latin, we find other significant changes. Although the current prayer begins, "Glory to God in the highest and peace to his people on earth" ...the Latin reads, as we will soon say, .."Glory to God in the highest and on earth peace to people of good will" inferring much about kind of people who are God's people.

"You take away the sin of the world" is now rendered "You take away the sins of the world…" not only making the English more faithful to the Latin but also allowing the words to better express what Matthew speaks of when referring to the sacrifice of Christ (Mat 26:28) as His "blood of the covenant, which will be shed on behalf of many for the forgiveness of sins."

"Only Begotten Son" replaces "only Son of the Father" stressing the uniqueness of Jesus.. the word "begotten" stresses that Christ had no beginning and was not born like we were.

Finally, the new translation has "have mercy on us" following "You are seated at the right hand of the Father" emphasizing our reliance on the mercy of Christ the Judge who from the right hand of His Father will return in glory to judge the living and the dead.
 

 

 
Sources: http://www.todayscatholicpueblo.org,http://catholicexchange.com (Louie Verrecchio), "A Biblical Walk Through The Mass", Edward Sri, www.wikipedia.com, & General Instruction of the Roman Missal