The Mass is both sacrifice and sacrament. As sacrifice it consists principally in man's activity, Christ's and ours, inspired and aided by grace, and of God’s approval and acceptance of what we do. Christ as man and Head of his Mystical Body represents that sacrifice of himself and us in him which he offered on Calvary. We his members endorse and ratify this, associating our own offering with his. It is in Christ's name as well as his own that the priest says: ‘Brethren, pray that my sacrifice and yours may be acceptable to God'. And God's reply is to receive and accept this offering as if saying once more: ‘This is my beloved Son in whom I am well pleased'.

It is needful to be quite clear about the nature of our activity. The priest says words and makes gestures which are essential to the offering of the sacrifice. There would be no Mass without them.