The Divine Service of the Lutheran Church is made up of three services: The Service of Preparation, The Service of the Word, and the Service of the Sacrament.
The Service of Preparation is Confession & Absolution. Confession & Absolution is based upon the power and authority Christ has given to the Church, exercised through the Office of the Holy Ministry. This power and authority is called the Office of the Keys:
“I will give you the keys of the kingdom of heaven, and whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven” (Matthew 16:19).
“Jesus said to them again, “Peace be with you. As the Father has sent me, even so I am sending you.” And when he had said this, he breathed on them and said to them, “Receive the Holy Spirit. If you forgive the sins of any, they are forgiven them; if you withhold forgiveness from any, it is withheld.” (John 20:21-23).