In our own day, fasting seems to have lost something of its spiritual meaning, and has taken on, in a culture characterized by the search for material well-being, a therapeutic value for the care of one’s body. Fasting certainly brings benefits to physical well-being, but for believers, it is, in the first place, a “therapy” to heal all that prevents them from conformity to the will of God. In the apostolic constitution Paenitemini of 1966, the Servant of God Paul VI saw the need to present fasting within the call of every Christian to “no longer live for himself, but for Him who loves him and gave himself for him … he will also have to live for his brethren.” Lent could be a propitious time to present again the norms contained in the apostolic constitution, so that the authentic and perennial significance of this long held practice may be rediscovered, and thus assist us to mortify our egoism and open our heart to love of God and neighbor, the first and greatest Commandment of the new Law and compendium of the entire Gospel.
The faithful practice of fasting contributes, moreover, to conferring unity to the whole person, body and soul, helping to avoid sin and grow in intimacy with the Lord. Saint Augustine, who knew all too well his own negative impulses, defining them as “twisted and tangled knottiness,” writes: “I will certainly impose privation, but it is so that he will forgive me, to be pleasing in his eyes, that I may enjoy his delightfulness.” Denying material food, which nourishes our body, nurtures an interior disposition to listen to Christ and be fed by His saving word. Through fasting and praying, we allow Him to come and satisfy the deepest hunger that we experience in the depths of our being: the hunger and thirst for God.
From the pope’s 2009 Lenten Message