Q. How can a man forgive sins?
The priest in Confession does not forgive sins by his own power, but by the power given to him by God in the sacrament of Holy order. Jesus Christ had the power to forgive sins because he was God as well as man. He gave this power to his apostles on the night of his resurrection when he said to them “Receive the Holy spirit. If you forgive the sins of any they are forgiven; if you retain the sins of any they are retained” (John 20, 22-23). This power of forgiving sin in the name of Jesus Christ the apostles passed on to those whom they ordained priests.
>In persona Christi = in the person of Christ