We fast to attain purity, but even before the fast, the intention itself must be pure and sincere. Our mind must be focused on pleasing God and becoming better, more obedient servants. We must seek this even before the fasting begins. We then approach the initial act of fasting with an earnest commitment.
So I say, walk by the Spirit, and you will not gratify the desires of the flesh. For the flesh desires what is contrary to the Spirit, and the Spirit what is contrary to the flesh. They are in conflict with each other, so that you are not to do whatever you want. [Galatians 5:16-17 (NIV)].
To advance toward God, purity of heart is essential, and fasting is a fundamental tool for purification. It provides a ritual state of purity in preparation for ceremonies and sacraments. In addition to providing physical purification, fasting prepares us mentally and spiritually.
Before the baptism, moreover, the one who baptizes and the one being baptized must fast, and others who can. And you must tell the one being baptized to fast for one or two days beforehand. [Didache].
Much misery and sadness come from negligent and thoughtless words. Our tongue finds no stillness when we feed our passions and gratify our lusts. As indecent words gush from our restless lips, we stir hatred and fuel conflicts that offend us and those around us.
Profane words damage our spiritual development while exalted speech and sublime words bring calmness and sobriety to our soul. May our lips ever be praising God and may our tongue eloquently glorify our Lord.
Fasting kills the desire of the self and the appetite of greed, and from it comes purity of the heart, purification of the limbs, cultivation of the inner and the outer being, thankfulness for blessings, charity to the poor, increase of humble supplication, humility, weeping and most of the ways of seeking refuge in God; and it is the reason for the breaking of aspiration, the lightening of evil things, and the redoubling of good deeds. It contains benefits which cannot be counted. It is enough that we mention some of them to the person who understands and is given success in making use of fasting, if God wills. [Imam Ja’far Al-Sadiq, The Lantern of the Path, Fasting].
By fasting, we turn away from physical pleasure and concentrate on matters of faith, seeking to prevent additional worldly impurities from contaminating us. Sealed from outside intrusions, the body begins a natural process of cleansing. This cleansing prepares the mind and spirit to approach God and to perceive the Divine Reality through sanctified senses.
The fasting mind gravitates toward loftier consciousness. At the same time, charity and acts of devotion further purify the heart. The cluttered thinking of a hectic material existence begins to dissipate. Prayer and remembrance of God then filter out the dreg and the impure thoughts, allowing greater awareness of God to prevail.
They [those who fear God] likewise well remember how fullness of bread increased not only carelessness and levity of spirit, but also foolish and unholy desires, yea, unclean and vile affections . . . Even a genteel, regular sensuality is continually sensualizing the soul, and sinking it into a level with the beasts that perish. It cannot be expressed what an effect a variety and delicacy of food have on the mind as well as the body; making it just ripe for every pleasure of sense, as soon as opportunity shall invite.
Therefore, on this ground also, every wise man will refrain his soul, and keep it low; will wean it more and more from all those indulgences of the inferior appetites, which naturally tend to chain it down to earth, and to pollute as well as debase it. Here is another perpetual reason for fasting; to remove the food of lust and sensuality, to withdraw the incentives of foolish and hurtful desires, of vile and vain affections. [John Wesley, The Works of John Wesley, Volume 5, Sermon 27.”Upon Our Lord’s Sermon on The Mount”].