From the apostolic letter “Inde a primis” (On promoting devotion to the Most Precious Blood of Our Lord Jesus Christ) of Pope St. John XXIII (+1963)

The Apostle’s wholesome advice comes to mind: “Keep watch, then, over yourselves, and over God’s Church, in which the Holy Spirit has made you bishops; you are to be the shepherds of that flock which he won for himself at the price of his own blood.” Now among the cares of our pastoral office, venerable brethren, we are convinced that, second only to vigilance over sound doctrine, preference belongs to the proper surveillance and development of piety, in both its liturgical and private expressions. With that in mind, we judge it most timely to call our beloved children’s attention to the unbreakable bond which must exist between the devotions to the Most Holy Name and Most Sacred Heart of Jesus — already so widespread among Christians — and devotion to the incarnate Word’s Most Precious Blood, “shed for many, to the remission of sins.”

As we now approach the feast and month devoted to honouring Christ’s Blood —- the price of our redemption, the pledge of salvation and life eternal — may Christians meditate on it more fervently, may they savour its fruits more frequently in sacramental communion. Let their meditations on the boundless power of the Blood be bathed in the light of sound biblical teaching and the doctrine of the Fathers and Doctors of the Church. How truly precious is this Blood is voiced in the song which the Church sings with the Angelic Doctor (sentiments wisely seconded by our predecessor Clement VI) :

All the world forgiveness of its world of sin. 

Unlimited is the effectiveness of the God-Man’s Blood — just as unlimited as the love that impelled him to pour it out for us, first at his circumcision eight days after birth, and more profusely later on in his agony in the garden, in his scourging and crowning with thorns, in his climb to Calvary and crucifixion, and finally from out that great wide wound in his side which symbolizes the divine Blood cascading down into all the Church’s sacraments. Such sur passing love suggests, nay demands, that everyone reborn in the torrents of that Blood adore it with grateful love.

The Blood of the new and eternal covenant especially deserves this worship of latria when it is elevated during the sacrifice of the Mass. But such worship achieves its normal fulfilment in sacramental communion with the same Blood, indissolubly united with Christ’s eucharistic Body. In intimate association with the celebrant the faithful can then truly make his sentiments at communion their own: “I will take the chalice of salvation and call upon the name of the Lord. . . The Blood of our Lord Jesus Christ preserve my soul for everlasting life. Amen.” Thus as often as they come worthily to this holy table they will receive more abundant fruits of the redemption and resurrection and eternal life won for all people by the Blood Christ shed “through the Holy Spirit.” Nourished by his Body and Blood, sharing the divine strength that has sustained countless martyrs, they will stand up to the slings and arrows of each day’s fortunes — even if need be to martyrdom itself for the sake of Christian virtue and the kingdom of God. Theirs will be the experience of that burning love which made St. John Chrysostom cry out:

Let us, then, come back from that table like lions breathing out fire, thus becoming terrifying to the Devil, and remaining mindful of our Head and of the love he has shown for us. . . This Blood, when worthily received, drives away demons and puts them at a distance from us, and even summons to us angels and the Lord of angels. . . This Blood, poured out in abundance, has washed the whole world clean. . . This is the price of the world; by it Christ purchased the Church… This thought will check in us unruly passions. How long, in truth, shall we be attached to present things? How long shall we remain asleep? How long shall we not take thought for our own salvation? Let us remember what privileges God has bestowed on us, let us give thanks, let us glorify him, not only by faith, but also by our very works. 

You know well enough that your ransom was not paid in earthly currency, silver or gold; it was paid in the precious blood of Christ; no lamb was ever so pure, so spotless a victim.” If only they would lend a more eager ear to the apostle of the Gentiles: “A great price was paid to ransom you; glorify God by making your bodies the shrines of his presence.” Their upright lives would then be the shining example they ought to be; Christ’s Church would far more effectively fulfill its mission to humanity. God wants all people to be saved, for he has willed that they should all be ransomed by the Blood of his only-begotten Son; he calls them all to be members of the one Mystical Body whose head is Christ. If only they would be more responsive to these promptings of his grace, how much the bonds of neighborly love among individuals and peoples and nations would be strengthened. Life in society would be so much more peaceable, so much worthier of God and the human nature created in his image and likeness.