Mass ends with the Concluding Rites, which consists of announcements, the priest’s greeting and blessing, the dismissal, and the kissing of the altar by the priest. These are not merely incidentals that can be ignored. They are an important part of the transition from the Mass back into our lives.
We are not only in communion with Jesus by receiving him on the altar. We are also in communion with him as we strive to do the work he left for us: proclaiming the Gospel, assisting those in need, teaching the next generation, evangelizing the world. In the Mass we have joined our sacrifice to that of Christ who offers his sacrifice to the Father. Christ gave himself over fully and freely to the will of the Father, even to death on the cross. The Father, who is always pouring himself out freely to the Son, receives that sacrifice and returns to us the presence of Christ in our midst.
This love between the Father and the Son is the Spirit who affects the transformation of bread and wine into the body and blood of Christ. Then, having been fed by the body of Christ under the forms of bread and wine, we are called to be the body of Christ in the world. We are called to pour out our hearts and lives as Christ did, as the Father does. This involves sacrifice and struggle, but the Spirit will strengthen and guide us. These sacrifices are what we will bring to join to Christ’s sacrifice in the next Mass.
The announcements help us to recognize this important fact by making known the immediate needs of this particular community in being the body of Christ. The announcements should not be long but should highlight one or two needs in serving the local community both inside and outside the Church.
These are followed by the greeting by the priest and the response by the people. This exchange, as with the Introductory Rites, recognizes the presence of Christ in all gathered. That presence is strengthened by the blessing of almighty God called down by the priest upon all gathered. In more solemn Masses, the blessing is tailored to the particular occasion.
The blessing is followed by the dismissal. This is not merely a formal act to get people of out of the church. It is a recognition of the love God has given us in this great sacrament and the way we are called to allow that love to bear fruit in this world through us. The new translation of the Roman Missal will include forms of dismissal written recently by Pope Benedict XVI to include more explicitly the call to mirror the love we have received: Go and announce the Gospel of the Lord. Go in peace, glorifying the Lord by your life. The people respond: Thanks be to God. Gratitude is the only possible response to God’s great love but it is more than the words spoken at this point. This thanks is lived out in lives of faithful service.
The final act of the Mass is the reverence of a kiss given by the priest to the altar. The altar is not merely the place where the sacrifice is offered. The altar is also a symbol of Christ Himself who receives our sacrifices and joins them to his to be offered to the Father. Reverencing the altar is a final act of reverence for Christ.
See the General instruction of the Roman Missal (No. 90) and Chapter 7 in Father Jeremy Driscoll’s book, “What Happens at Mass.”