Fasting

They are the three fundamental practices also dear to the Hebrew tradition because they contribute to the purification of man before God (cf. Mt 6:1-6,16-18).  Such exterior gestures, which are done to please God and not to obtain the approval and consensus of men, are acceptable to him if they express the determination of the heart to serve him with simplicity and generosity. 

One of the Lenten Prefaces also reminds us of this with regards to fasting, as we read this singular expression: "ieiunio...mentem elevas: with fasting the spirit is raised" (Preface IV). 

Fasting, to which the Church invites us in this particular season, certainly is not motivated by the physical or aesthetical order, but stems from the need that man has for an interior purification that detoxifies him from the pollution of sin and evil; it educates him to that healthy renunciation which releases the believer from the slavery to self; that renders him more attentive and open to listen to God and to be at the service of the brethren.

For this reason fasting and the other Lenten practices are considered the traditional Christian spiritual "arms" used to fight evil, unhealthy passions, and vice.  Concerning this, I would like to listen, together with you, to a brief comment of Saint John Chrysostom. 

"As at the end of winter," he writes, the summer season returns and the navigator launches his boat into the sea, the soldier polishes his arms and trains the horse for battle, the farmer sharpens the scythe, the wayfarer, strengthened, continues his journey, and the athlete sets aside his vestments and prepares for the race; so we too, at the start of this fast, like returning to a spiritual springtime, we polish the arms like the soldiers, we sharpen the scythe like the farmers, and as mariners we launch the boat of our spirit to confront the waves of senseless passions, like the wayfarer we continue the journey to heaven, and as the athlete we prepare ourselves for the fight by totally setting aside everything."