Two good explanations of the benefits of Private Confession And Absolution are here:
An Explanation of The Small Catechism, Confession
Luke 14: 7-11
7Now he told a parable to those who were invited, when he noticed how they chose the places of honor, saying to them, 8"When you are invited by someone to a wedding feast, do not sit down in a place of honor, lest someone more distinguished than you be invited by him, 9and he who invited you both will come and say to you, 'Give your place to this person,' and then you will begin with shame to take the lowest place. 10But when you are invited, go and sit in the lowest place, so that when your host comes he may say to you, 'Friend, move up higher.' Then you will be honored in the presence of all who sit at table with you. 11For everyone who exalts himself will be humbled, and he who humbles himself will be exalted."