And one [angel] cried to another and said: “Holy, holy, holy is the Lord of hosts; the whole earth is full of His glory!” Isaiah 6:3
Early in the history of Christianity, “catechesis” became the norm for instructing new believers in the faith. Catechisms were written in question-and-answer formats—teachers would ask a question and converts would repeat the memorized answer. The most famous catechism used for children and young believers was written between 1646 and 1647, the Westminster Shorter Catechism. The first question has become famous: “What is the chief end of man?” The answer: “Man’s chief end is to glorify God, and to enjoy him forever.”
Man’s purpose, along with all creation—including the angels—is to glorify God. Isaiah saw angels glorifying God in his vision (Isaiah 6:1-3), and John saw angels doing the same in his vision of heaven (Revelation 5:11-12). John reckoned the number of angels he saw as “ten thousand times ten thousand” or one hundred million. It was probably not meant to be an exact number, but it was John’s way of saying “too many to count”—the number of angels praising God in heaven.
Mankind and angels have the same eternal purpose: to glorify God and enjoy Him forever.
Let earth and heaven combine, angels and men agree, to praise in songs divine the incarnate Deity. Charles Wesley