Since the introduction of the new liturgical texts for Mass this past Advent, we have become accustomed to new words and new expressions in our common prayer. Some of the changes in the Mass are obvious and readily noticed. But not all.
There is one change that seems ever so slight and may even go unnoticed. After the consecration, the priest no longer says, “Let us proclaim the mystery of faith.” Instead, he simply announces “The mystery of faith.” Attention to the theological reasons for this change opens us to a richer appreciation of the Eucharist.

Ever since the seventh century, the words “The mystery of faith” have been part of the institution narrative (i.e. the words of consecration). Before the Second Vatican Council’s reform of the liturgy, the priest would say these words inaudibly as part of the consecration of the wine. With the liturgical revisions of 1969, the formula was moved to its present position after the consecration of the wine and the priest was instructed to say the formula audibly “Let us proclaim the mystery of faith.”
With our new liturgical texts, the priest now simply says “The mystery of faith.” Why the change? What is the meaning of this formula? What is its purpose in the canon of the Mass?

The priest’s words were shortened in the new missal text to render the Latin text ( mysterium fidei) more faithfully. In fact, this shorter formula conveys more accurately the purpose of these words. These words are not an invitation to proclaim the mystery of faith. However, the response “Christ has died, Christ is risen, Christ will come again” does exactly that: it proclaims or declares what the mystery is. And, for that reason, it is no longer used.

Immediately after the consecration, in the anamnesis (memorial) of the Mass, the priest himself proclaims or declares what the mystery is. He recounts the death that Jesus endured for our salvation, his glorious resurrection and ascension into heaven. But before he does that, he says “The mystery of faith.” This is an invitation for the people to make an acclamation, a response to the mystery of faith now present in the Body and Blood of Christ.

An acclamation is different than a proclamation. An acclamation is addressed directly to someone. An acclamation is spoken in the second person, whereas a proclamation is in the third person. In the new missal text, the people speak directly to the Lord himself now present in the Eucharist.

This distinction between proclamation and acclamation is clearly seen in the responses in the new missal. The people now have the choice of using one of three options. They may say, “We proclaim your death, O Lord, and profess your resurrection until you come again.” Or, “When we eat this Bread and drink this Cup, we proclaim your death, O Lord, until you come again.” Or, “Save us, Savior of the world, for by your cross and resurrection, you have set us free.” Even when two of these formulas use the word “proclaim,” the whole formula itself is not a proclamation, but an acclamation, because the words in the second person are directed to the Lord.

The phrase “The mystery of faith” that invites our response after the consecration is one of the most powerful phrases in the Roman liturgy. The word “mystery” is a densely rich biblical word. It means God’s plan for the creation of the world and for our salvation hidden for all eternity and gradually revealed and accomplished in Christ.
The mystery is God bringing us to share in his own divine life through the life, death and resurrection of Christ. It is God reconciling and restoring the world in Christ (Eph 1:9-14). The mystery is Christ in the paschal events made sacramentally present. The letter to the Colossians speaks of the mystery as “Christ himself, in whom are hidden all the treasures of wisdom and knowledge” (Col 2:2-3). Thus, Christ himself is the mystery.

When the priest says immediately after the consecration, “The mystery of faith,” he is drawing our attention to Christ, Crucified, Risen and Ascended, now among us. The words of the priest remind us that Christ is here among us to form us as his body “the church, which is his body, the fullness of him who fills all in all” (Eph 1:23). Thus, Jesus now sacramentally, truly and really in our midst, is bringing to completion in us the fullness of our redemption.

In sacrament, the Eucharist is the mystery of faith: Jesus accomplishing our salvation through his sacrificial death on the cross and his glorious resurrection. How can our hearts not overflow with wonder and awe! How fervent should be our spontaneous response to this great gift! Ultimately, the Eucharist, now present on our altar after the consecration, demands our response not simply in words of acclamation, but in a life that is a true proclamation of Easter faith.