In the Eucharist, Jesus calls us and offers us the grace to become, like Him, a "gift" offered to the Father for souls. Becoming a "gift" for God means that we offer Him our lives, all our joys and sorrows. It means also accepting and offering to Him all the little sacrifices of daily life, our struggles, toils and labors. It can also mean making extra little penances or sacrifices to prove our love for God and to add efficacy to our prayers. It does not suffice when we resolve in the morning: "I do want to make expiation; indeed, I am going to Holy Mass; then I will have done more than enough." The Lord demands that to His deed, we also add ours. At Holy Mass and Holy Communion, we receive the proper strength for the sacrifice of expiation from Christ, the Redeemer. We must work with this strength as long as it is day. We do not know how long we will be able to work Let us begin therefore immediately after the Holy Mass to convert this strength of expiatory sacrifice, which has been given to us into His deed. Let us ask our holy Guardian Angel to open our eyes in this matter. We will be astonished how many things around us are waiting for us!
Thus, to this Sacrifice of the Holy Mass, God wants us to add our own, all the little hardships throughout our day, the many little acts of kindness or helpfulness which we can show to others, the patience with difficult persons or situations, and much more. During Lent especially, we also want to impose upon ourselves a small penance or fast. These small penances and acts of self-denial which we impose on ourselves can be offered in expiation for sin, first for our own sins and then for others. It is important that we add also the intention, as we learned from Our Lady at Fatima: for love of God, in reparation for the sins committed against the Immaculate Heart of Mary, for the conversion of sinners. We can add also the particular intentions in our heart, "In reparation for my lack of charity this morning," "In expiation for my son who no longer practices the faith," or "In expiation for this priest who is causing scandal in the Church."
(Opus Sanctorum Angelorum, Lenten Circular Letter, 2018)