1. Penance keeps our low nature subject to reason.
Make the body do what we want it to do in all things. Regarding food we eat too much.
Curé d'Ars. Jean Vianney (1786-1859) lived to a rule of one meal a day.
2. To obtain graces. If praying is not going well a little mortification brings grace. Brings cheerfulness. Nothing gives more joy than doing hard things for Christ. To neglect penance begets sloth. Body has to be kept in it’s right place.
3. To atone for Sins and make sanctification for temporal punishment due for Sins.
If we don’t do mortification for our sins in this life we’ll have to do it in the next. Why not do it here. You’ve quite a bit to do remember. Consider the day wasted if you have not done some act of mortification. O’ Lord the saints had a great love for penances.
FR NORRIS WRITES ON PENANCE AND HOW IMPORTANT THE SACRAMENT IS AND HOW MUCH ADDITIONAL GRACE WE CAN OBTAIN BY PRACTICING IT.