The Gloria in Excelsis is one of the oldest hymns of the Christian Church. It is a hymn of adoration that celebrates God’s glory manifested in the gift of His Son. The name Gloria in Excelsis comes from the first words of the Latin version.
The opening words of the Gloria were sung by the angels at the birth of Jesus (Luke 2:14). Luther says of this part, “It did not grow; nor was it made on earth; it came down from heaven.”
After singing the Gloria in Excelsis, comes the Collect of the Day. The Collect of the Day is a prayer designed to do something special. The word collect means to bring or gather together.
The Collect of the Day is a prayer that brings or gathers together the main thought from the Scripture readings that will soon be read. It offers a prayer to God for the congregation on that thought.
All the collects used in the Lutheran Church were completed by 800 A.D. Of course, there are new collects written and old ones modified, but generally speaking, the collects have been in use for 1300 years.