"The grace of purity comes only from Our Lord. Communion gives it, increases it, strengthens it, preserves and maintains it against all the assaults of hell, the world, and the flesh. You drink there the virginal Blood of the spotless Lamb. It is absolutely true that, without Communion, one cannot be chaste." Source: St. [...]
"Augustine says in his book on the Sentences of Prosper (Lanfranc, De Corp. et Sang. Dom. xiii): 'Under the species which we behold, of bread and wine, we honor invisible things, i.e. flesh and blood.'" Source: St. Thomas Aquinas, Summa Theologica
"If one could understand all the blessings contained in Holy Communion nothing else would content the heart of man. The miser would no longer run after his treasures, nor the ambitious after glory. Everyone would shake the dust of earth from their feet and would fly towards heaven." Source: St. John Vianney, The Meditations [...]
"I wish briefly to reaffirm the fact that eucharistic worship constitutes the soul of all Christian life. In fact, Christian life is expressed in the fulfilling of the greatest commandment, that is to say, in the love of God and neighbor, and this love finds its source in the blessed Sacrament, which is commonly called [...]
"All gather together. Christians come together in one place for the Eucharistic assembly. At its head is Christ himself, the principal agent of the Eucharist. He is high priest of the New Covenant; it is he himself who presides invisibly over every Eucharistic celebration. It is in representing him that the bishop or priest acting [...]
“'Parents often entrust their offspring to others to feed; but I', says He, 'do not so, I feed you with My own flesh, desiring that you all be nobly born, and holding forth to you good hopes for the future.'” Source: St. John Chrysostom, Homily 46
"For those who are receptive this blood bestowed and accomplished all that they need to be saved and made perfect. But since its gift of life and grace is in proportion to the soul’s readiness and desire, it deals death to the wicked. So it gives death rather than life to those who receive it [...]
"What use is life to me, if I do not spend it wholly in loving and pleasing Thee, my beloved Redeemer, who hast poured out Thy whole life for me? And what have I to love, if it is not Thee, who art all beauty, all condescension, all goodness, all loving, all worthy of love? [...]
"Form cannot be changed into form, nor matter into matter by the power of any finite agent. Such a change, however, can be made by the power of an infinite agent, which has control over all being, because the nature of being is common to both forms and to both matters; and whatever there is [...]
"If the Eucharist expresses the irrevocable nature of God's love in Christ for his Church, we can then understand why it implies, with regard to the sacrament of Matrimony, that indissolubility to which all true love necessarily aspires." Source: Pope Benedict XVI, SACRAMENTUM CARITATIS (Sacrament of Charity), 2/22/2007