13 By virtue of its close relationship to the sacrifice of Golgotha, the Eucharist is a sacrifice in the strict sense , and not only in a general way, as if it were simply a matter of Christ's offering himself to the faithful as their spiritual food. The gift of his love and obedience to the point of giving his life (cf. Jn 10:17-18) is in the first place a gift to his Father. Certainly it is a gift given for our sake, and indeed that of all humanity (cf. Mt 26:28; Mk 14:24; Lk 22:20; Jn 10:15), yet it is first and foremost a gift to the Father : “asacrifice that the Father accepted, giving, in return for this total self-giving by his Son, who 'became obedient unto death' ( Phil 2:8), his own paternal gift, that is to say the grant of new immortal life in the resurrection”. In giving his sacrifice to the Church, Christ has also made his own the spiritual sacrifice of the Church, which is called to offer herself in union with the sacrifice of Christ. This is the teaching of the Second Vatican Council concerning all the faithful: “Taking part in the Eucharistic Sacrifice, which is the source and summit of the whole Christian life, they offer the divine victim to God, and offer themselves along with it”.
Source: Ecclesia de Eucharistia (Vatican.va)