On Mount Moriah, Isaac, Abraham's only and beloved son, was not sacrificed; on Calvary, Jesus suffered and died for all of us, pro peccatis, because of our sins. This fruit of expiation and propitiation also reaches the souls of those who have gone before us and who are purified in Purgatory, awaiting the wedding garment to enter Heaven.
The Eucharistic sacrifice accomplishes, by itself and by its own virtue, the forgiveness of sins; "but it operates in a mediate way.... For example, a person who asks God without attending the sacrifice for the grace to change his life and to go to confession, will obtain it only by virtue of his fervor and his requests...; but if he hears Mass for this purpose, it is certain that he will obtain this favor efficaciously, provided he does not oppose any obstacles to it".
Jesus Christ, in offering himself to the Father, asks for everyone. He lives to intercede for us, so what better time could we find than during Holy Mass to ask for what we need so much?
Each Mass is offered for the whole Church, which in turn pleads for the whole world. "Every time a Mass is celebrated it is the blood of the Cross that is poured out like rain on the world." [...] Along with this general fruit of the Mass, there is also a special fruit, in different ways, for those who participate in the Holy Sacrifice: those who have procured that it be celebrated; for the priest there is a very special fruit that cannot be renounced, since it depends on his meritorious will that the Mass be said; the acolytes, the cantors... and all the holy people who are present at the Sacrifice, each one according to his dispositions, participate in this special fruit: all those present, whose faith and dedication you know well.... For them and all theirs, for the forgiveness of their sins and the salvation they hope for, we offer you and they themselves offer you this sacrifice of praise to you, eternal God, living and true.
In addition to the fruits of praise and adoration of God, the Holy Mass also produces, in an infinite and unlimited way in itself, the fruits of remission of our sins and of impetration of all that we need, but they are finite and limited according to our dispositions. That is why the preparation of the soul with which we approach to participate in this unique Sacrifice, and the moments of recollection once the sacred action is over, are so important. Are you there," asks the Holy Curé of Ars, "with the same dispositions as the Blessed Virgin on Calvary, since it is a question of the presence of the same God and the consummation of the same sacrifice?
Let us ask Our Lady that the celebration or participation in the Eucharistic sacrifice may be for us the source where our desires for God are satiated and increased.