For every high priest chosen from among men is appointed to act on behalf of men in relation to God, to offer gifts and sacrifices for sins. He can deal gently with the ignorant and wayward, since he himself is beset with weakness. Because of this he is bound to offer sacrifice for his own sins as well as for those of the people. And one does not take the honor upon himself, but he is called by God, just as Aaron was. Hebrews 5:1–4 (RSV)
'As a called and ordained minister of the Church of Christ, and by His authority, I, therefore, declare to you the entire forgiveness of all your sins, in the Name of the Father, and of the Son, and of the Holy Spirit. Amen"
The 'amen' had hardly left my lips when he stopped me and said, 'I just realized, that means me, I am forgiven!' That promise had been spoken in his hearing the whole of his life but became real at that moment. His sins were forgiven.
I had brought the Supper to him for years, but it was that moment as the words of absolution were proclaimed to him that the Holy Spirit allowed him to hear them as God's promise for him.
When people ask me why I haven't retired yet, moments like this are the reason. The promise of grace and mercy for sinners such as myself will not let me go. The blessing of pronouncing the absolution week in and week out is the cool drink of water to thirsting souls. It is the joy of the pastoral office to be allowed to offer such Good News.
The Office of the Keys, the pastor's role, is to announce the Gospel to the gathered faithful so they might know, or at last discover, that they are forgiven and beloved of God the Father.