St John Vianney sometimes delayed giving absolution to a penitent, asking that he or she remain some days in his village after which he would give the absolution. He did this not to hold control over the person, but so that the person's heart could grow during those days and so be more able to receive the grace of mercy which God desired for that person. This is one of the ways in which St John Vianney insisted on the goodness of God; that human nature, not God, is called to change, precisely because God is all good at all times.
So often we can respond to our own sinfulness by a feeling of unworthiness, an attitude which closes us off somewhat from the goodness of God. In fact, because God is overwhelming in his mercy to us, my attitude should really be to seek to make reparation to his tremendous love for me.
St John Vianney's own life had been turned upside down, and then modelled upon God's mercy, so that he, as a priest, became a conduit of divine mercy to others. God's mercy is the focus and centre of human life and it is the Confessional that enables all of us to be established upon this true foundation.