During Lent, the Church asks us to prepare for Christ's passion and resurrection by making small sacrifices, traditionally in the form of prayer, fasting, and almsgiving. But why do we sacrifice? What is a sacrifice, anyway?
St. Thomas Aquinas observes that "sacrifice" comes from the Latin word: Sacrificium.Sacrificium comes from sacer (holy) and facere (do or make). A sacrifice is a making-holy. Not only that, but St. Thomas' discussion of sacrifice reveals so much about our nature and our relationship to God. He describes a sacrifice as a bodily act of offering to God a gift that is broken or transformed so that we might return to God.
A bodily act
Sacrifice is fundamentally a religious act of offering a gift to God. But isn't this a bit strange? If God is all spirit, how could he possibly need our physical offerings?
St. Thomas explains that our physical offerings are not really for God's benefit, but for us. As a unity of body and soul, the human person experiences reality through the physical senses. Even God presents himself to us through the sensible things of creation. It is fitting, then, that we present ourselves to God through sensible things as well. Think of the Sacraments: all are visible signs of invisible grace. Lenten fasting and sacrifices are tiny sacramental signs of the true gift we give God: ourselves, body, and soul.
A gift is broken or transformed
However, a sacrifice is not just any gift. St. Thomas explains that an offering only becomes a sacrifice when it is changed: the goat is slaughtered, the bread is broken, and the grain is consumed by fire. In being transformed, the offering is set apart and made holy. Christ himself, the consummate sacrifice, was mutilated, pierced, and subjected to death.
But for these to be real sacrifices, something must be broken and transformed. Lenten practices of prayer, fasting, and almsgiving break little cracks in the brittle illusion of our self-sufficiency. They invite us to acknowledge our brokenness, susceptible as we all are to the corrupting effects of sin. And they invite God's grace to transform us and make us holy. "The sacrifice acceptable to God is a broken spirit; a broken and contrite heart, O God, thou wilt not despise" (Psalm 51:17).
Return to God
Why, then, do we sacrifice? We do it to return to God, and this return happens in two distinct ways. First, through sacrifice, we "return to God" in the sense of giving back what we owe him. Of course, we can't possibly repay God for his gifts with an equal return—he is the source of our very existence! We owe him everything. Nevertheless, we can do our part: our small personal sacrifices signify our return to God. And thankfully, Christ lovingly repaid our dues in full through his perfect self-sacrifice, which we too can offer to God every time we participate in the Mass.
Second, through sacrifice, we "return to God" in the sense of turning back towards him over and over again. Like the Israelites, we are constantly turning away from God and towards sin. As God called Israel to repentance through the prophets, he still calls us: "Return to me with all your heart" (Joel 2:12).
Lenten practices help us shed bad habits and self-love. St. Thomas says these religious acts purify us to orient ourselves more single-mindedly toward God. When we respond thus to the divine call—when we offer ourselves up, body and soul, to be broken and transformed by his merciful love—we are made holy.