Why do we say Mass is a sacrifice when the Letter to the Hebrews indicates that Christ offered only one sacrifice on the cross?

Chapter 9 of the Letter to the Hebrews addresses the sacrifice of Jesus:  Verses 25-28 read, “Not that [Christ] might offer Himself there again and again, as the high priest enters year after year into the sanctuary with blood that is not his own; if that were so He would have had to suffer death over and over from the creation of the world.  But now He has appeared at the end of the ages to take away sins once for all by His sacrifice.  Just as it is appointed that men die once, and after death be judged, so Christ was offered up once to take away the sins of many; He will appear a second time not to take away sin but to bring salvation to those who eagerly await Him.”  Further, Hebrews 7:27 states,  “Unlike the other high priests, [Jesus] has no need to offer sacrifice day after day, first for His own sins and then for those of the people; He did that once for all when He offered Himself.”  To isolate these verses from the rest of Sacred Scripture and simply take them for face value would lead one to conclude that there could be no other sacrifice–  Christ sacrificed Himself, it is over and done with, and that is it period.  However, such a view is myopic to say the least.

Please note that in no way do we as Catholics believe that Christ continues to be crucified physically or die a physical death in heaven over and over again.  However, we do believe that the Mass does participate in the everlasting sacrifice of Christ.  First, one must not separate the sacrifice of our Lord on the cross from the events which surround it.  The sacrifice of our Lord is inseparably linked to the Last Supper.  Here Jesus took bread and wine.  Looking to St. Matthew’s text (26:26ff), He said over the bread, “Take this and eat it.  This is my body”; and over the cup of wine, “This is my blood, the blood of the covenant, to be poured out in behalf of many for the forgiveness of sins.”  The next day, on Good Friday, our Lord’s body hung on the altar of the cross and His precious blood was spilt to wash away our sins and seal the everlasting, perfect covenant.  The divine life our Lord offered and shared for our salvation in the sacrifice of Good Friday is the same offered and shared at the Last Supper.  The Last Supper, the sacrifice of Good Friday, and the resurrection on Easter form one saving, life-giving event.

Second, one must have a nuanced understanding of time.  One must distinguish chronological time from kairotic time as found in Sacred Scripture.  In the Bible, chronos refers to chronological time– past, present, and future– specific deeds which have an end point.  Kairos or kairotic time refers to God’s eternal time, time of the present moment which recapitulates the entire past as well as contains the entire future.  Therefore, while our Lord’s saving event occurred chronologically about the year AD 33, in the kairotic sense of time it is an everpresent reality which touches our lives here and now.  In the same sense, this is why through Baptism we share now in the mystery of Christ’s passion, death, and resurrection, a chronological event that happened almost 2,000 years ago but is still efficacious for us today.

With this in mind, we also remember that our Lord commanded, as recorded in the Gospel of St. Luke (22:14ff) and St. Paul’s First Letter to the Corinthians (11:23ff), “Do this in remembrance of me.”  Clearly, our Lord wanted the faithful to repeat, to participate in, and to share in this sacramental mystery.  The Last Supper event which is inseparably linked to Good Friday (and the resurrection) is perpetuated in the Holy Mass for time eternal.

The Mass therefore is a memorial.  In each of the Eucharistic Prayers, the anamnesis or memorial follows the words of consecration, whereby we call to mind the passion, death, resurrection, and ascension of the Lord.  However, this memorial is not simply a recollection of past history in chronological time, but rather a liturgical proclamation of living history, of an event the continues to live and touch our lives now in that sense of kairotic time.  Just as good orthodox Jews truly live the Passover event when celebrating the Passover liturgy, plunging themselves into an event which occurred about 1200 years before our Lord, we too live Christ’s saving event in celebrating the Mass.  The sacrifice which Christ offered for our salvation remains an everpresent reality:  “As often as the sacrifice of the cross by which ‘Christ our Pasch is sacrificed’ is celebrated on the altar, the work of our redemption is carried out” (Dogmatic Constitution on the Church, #3).  Therefore, the Catechism asserts, “The Eucharist is thus a sacrifice because it re-presents (makes present) the sacrifice of the cross, because it is its memorial and because it applies its fruit” (#1366).

Therefore, the actual sacrifice of Christ on the cross and the sacrifice of the Mass are inseparably united as one single sacrifice:  The Council of Trent in response to Protestant objections decreed, “The victim is one and the same:  the same now offers through the ministry of priests, who then offered Himself on the cross; only the manner of offering is different,” and “In this divine sacrifice which is celebrated in the Mass, the same Christ who offered Himself once in a bloody manner on the altar of the cross is contained and is offered in an unbloody manner.”  For this reason, just as Christ washed away our sins with His blood on the altar of the cross, the sacrifice of the Mass is also truly propitiatory.  The Lord grants grace and the gift of repentance, He pardons wrong doings and sins.  (Confer Council of Trent, Doctrine on the Most Holy Sacrifice of the Mass).

Moreover, the Mass also involves the sacrifice of the whole Church.  Together we offer our prayers, praise, thanksgiving, work, and sufferings to our Lord, thereby joining ourselves to His offering.  The whole Church is united with the offering of Christ:  this is why in the Eucharistic Prayers we remember the Pope, the Vicar of Christ; the Bishop, shepherd of the local diocese; the clergy who minister  in persona Christi to the faithful; the faithful living now; the deceased; and the saints.

The Constitution on the Sacred Liturgy of Vatican II summed it up well:  “At the Last Supper, on the night He was betrayed, our Savior instituted the eucharistic sacrifice of His Body and Blood.  This He did in order to perpetuate the sacrifice of the Cross through the ages until He should come again, and so to entrust to His beloved Spouse, the Church, a memorial of His death and resurrection:  a sacrament of love, a sign of unity, a bond of charity, a paschal banquet in which Christ is consumed, the mind is filled with grace, and a pledge of future glory is given to us” (#47).  Each time we celebrate Mass, let us give thanks to our Lord for the beautiful, precious gift of the Mass and the Holy Eucharist.