The Catechism in Questions & Answers

613. What is a divine service?

Divine service is the activity of God upon human beings. At the same time, it is a work of human beings for God.
In the divine service, people come together to worship God, praise Him, and thank Him. They also gather in order to hear the word of God and receive the sacraments.
Thus divine service is an encounter between God and man. In the divine service, the congregation perceives the presence of the triune God and experiences that God serves them in love.