This is the highest form of worship in the Catholic Church which is an eternal presentation in unbloody fashion the sacrifice of Calvary which opened the gates of heaven to us all, which made Heaven accessible again to God's sinful creatures.
NOTE: The Eastern Catholic (and Orthodox) brethren refer to the Mass as the Divine Liturgy. Here the term is used interchangeably.
During the Lord's Prayer (Our Father): Holding hands and use of the orans gesture (hands held upward with palms facing forward
by Terry Garrity, CAA President
Use of the orans gesture is prohibited and holding hands is questionable--but what constitutes an orans gesture requires some parsing and charity must prevail no matter what. Popular expressions of personal piety enjoy fairly wide allowance in the Mass.
How do I explain that the Mass is not a “re-sacrificing” of Jesus?
by Steve O'Keefe, Staff Apologist
To understand what is going on in the Mass, one first has to understand the notion of “participation”. Participation refers to how God allows us, as members of the body of Christ, to share in a prerogative which is proper to Himself. One example would be our status as children of God, which we receive from Christ in baptism [Gal 3:26]. Another example: Saint Paul says we become “co-heirs” with Christ to the kingdom of Heaven [Rom 8:17]. A third example; Paul says we become “co-laborers” with Christ in the work of salvation [1Cor 3:9]. So participation is the way God allows us to join in what Jesus does.
One of the things Jesus does is offer Himself to the Father as the sacrifice for our salvation. This sacrifice took place outside Jerusalem in 33AD, but we learn in the Bible that the presentation of this sacrifice before God takes place in eternity. The book of Revelation gives us a vision of this. John sees the worship which takes place in Heaven, and at its center is the Lamb of God standing wounded on an altar [Rev 5:6]. This is an image of Jesus eternally presenting
His sacrifice before God on our behalf. It is why the letter to the Hebrews says, “Jesus lives forever to make intercession for us” [Heb 7:25].
At the Last Supper, Jesus showed His disciples how the Church would participate in that eternal presentation of the one sacrifice [1Cor 10:16]. Through the Eucharist, the Lamb of God is made present on the altar during the Mass. So the Mass is not a re-sacrifice of Jesus, it is our participation in the eternal presentation of that single sacrifice. [CCC 1368]