Therefore you hear that as often as sacrifice is offered, the Lord's death, the Lord's resurrection, the Lord's ascension and the remission of sins is signified, and will you not take the Bread of life daily? He who has a wound needs medicine. The wound is that we are under sin; the medicine is the heavenly and venerable Sacrament.

St. Ambrose: On the Sacraments , 5, 4, 25.