There are three things by which faith stands firm, devotion remains constant, and virtue endures. They are prayer, fasting and mercy. Prayer knocks at the door, fasting obtains, mercy receives. Fasting is the soul of prayer, mercy is the lifeblood of fasting. Let no one try to separate them; they cannot be separated. If you have only one of them or not all together, you have nothing. So if you pray, fast; if you fast, show mercy; if you want your petition to be heard, hear the petition of others. If you do not close your ear to others you open God’s ear to yourself.
When you fast, see the fasting of others. If you want God to know that you are hungry, know that another is hungry. If you hope for mercy, show mercy. If you look for kindness, show kindness. If you want to receive, give. If you ask for yourself what you deny to others, your asking is a mockery.
—Peter Chrysologus, Sermon 43