12. Besides all this, the grace of mutual charity among the living, which derives from the Sacrament of the Eucharist so great an increase of strength, is further extended by virtue of the Sacrifice to all those who are numbered in the Communion of Saints. For the Communion of Saints, as everyone knows, is nothing but the mutual communication of help, expiation, prayers, blessings, among all the faithful, who, whether they have already attained to the heavenly country, or are detained in the purgatorial fire, or are yet exiles here on earth, all enjoy the common franchise of that city whereof Christ is the head, and the constitution is charity. For faith teaches us, that although the venerable Sacrifice may be lawfully offered to God alone, yet it may be celebrated in honour of the saints reigning in heaven with God Who has crowned them, in order that we may gain for ourselves their patronage. And it may also be offered - in accordance with an apostolic tradition - for the purpose of expiating the sins of those of the brethren who, having died in the Lord, have not yet fully paid the penalty of their transgressions.
13. That genuine charity, therefore, which knows how to do and to suffer all things for the salvation and the benefit of all, leaps forth with all the heat and energy of a flame from that most holy Eucharist in which Christ Himself is present and lives, in which He indulges to the utmost. His love towards us, and under the impulse of that divine love ceaselessly renews His Sacrifice. And thus it is not difficult to see whence the arduous labours of apostolic men, and whence those innumerable designs of every kind for the welfare of the human race which have been set on foot among Catholics, derive their origin, their strength, their permanence, their success.
14. These few words on a subject so vast will, we doubt not, prove most helpful to the Christianflock, if you in your zeal, Venerable Brethren, will cause them to be expounded and enforced as time and occasion may serve. But indeed a Sacrament so great and so rich in all manner of blessings can never be extolled as it deserves by human eloquence, nor adequately venerated by the worship of man. This Sacrament, whether as the theme of devout meditation, or as the object of public adoration, or best of all as a food to be received in the utmost purity of conscience, is to be regarded as the centre towards which the spiritual life of a Christian in all its ambit gravitates; for all other forms of devotion, whatsoever they may be, lead up to it, and in it find their point of rest. In this mystery more than in any other that gracious invitation and still more gracious promise of Christ is realised and finds its daily fulfilment: "Come to me all ye that labour and are heavily burdened, and I will refresh you" (St. Matt. xi., 28).