Why does the pastor say "I" during absolution?

Here is what I think is happening during Absolution. The pastor says "I" because he is in Christ's seat when he gives absolution, because when he does so he acts in accordance with Christ's command and his word of promise.

As to why we need absolution during out life here on earth, we have to do it again not because we necessarily flop back and forth between salvation and damnation, but because we sin--we are sinners as touching our sinful acts and desires and justified as touching our relationship with the Father through Christ. Because we are both at the same time, we still struggle with the sin we were born with and into. The more we grind Adam into dust, the more Godly our acts.

Finally, keep in mind that the objectivity of what is going on is important to Lutherans--it is important we believe the minister when he says our sins are forgiven, because without belief we cannot benefit from the promise of absolution God is iffering through Jesus Christ via the minister.