“Two moments in salvation history hinge on a single Latin word: fiat — ‘let it be done,’” she wrote. “The first came at the dawn of creation: dixitque Deus: fat lux. Et facta est lux — ‘Then God said: Let there be light, and there was light’” (Gn 1:3).

Millennia later, in a quiet corner of Nazareth, another fiat was spoken — not by God, but in answer to the angel of God: dixit autem Maria: Ecce ancilla Domini; fiat mihi secundum verbum tuum — “Mary said, ‘Behold, I am the handmaid of the Lord. May it be done to me according to your word’” (Lk 1:38).

And that is how easily, yet how momentously, Mary became a mother, God became man, and human history was split in half.

Abigail saw how the world’s redemption hung on Mary’s “Yes.” This is the entire understanding of the title “co-redemptrix.” Mary is not the Redeemer, Jesus is. However, to become man, God selected a special woman for him to be born in human history. So, then, the title simply refers to Mary accepting the responsibility of giving birth to the Redeemer by saying, “Yes” to God.

“In Genesis, God’s fiat is a command — a divine utterance that births light, order and life,” Abigail continued. “It’s the voice that carves the cosmos from chaos. The Latin fiat lux isn’t just poetic, it’s performative.” In other words, God speaks, and atoms rush to obey.

“The Virgin’s fiat is not a command — it’s her consent,” my friend wrote. “Spoken in obscurity, without fanfare, her ‘yes’ is no mere passive acceptance. It is vigorous, courageous and world-altering. Mary becomes the hinge of redemption. She doesn’t ask for guarantees, she only asks how the event will take place.” 

Already full of grace, but now overshadowed by the Holy Spirit of God, whose clouds once thundered as they enshrouded the peaks of Sinai (Ex 19:9), Mary becomes the first to welcome the Word as he is made flesh.

The Virgin’s word of consent didn’t sound only in Nazareth. Echoes of her fiat rang out in Bethlehem, Jerusalem and Egypt; in Cana, on Calvary and in the Upper Room, when the Queen Mother of the King of Kings was once again overshadowed by the Divine Spirit. 

Mary’s fiat reverberates through every Christ-centered Advent or Christmas chant, hymn, carol, anthem and song. 

Abigail picked up on that theme. “In O Come, O Come Emmanuel and other Advent music, longing touches fulfillment. Melodies highlight theology. Lyrics of longing allow singers to participate in longing to experience the mystery of the Incarnation,” she wrote. 

In every party and celebration of the season, believers echo Mary’s profound trust “in God, my savior,” as they wait for Christmas morn. Her fiat rings throughout the liturgies of the four Sundays of Advent.

Home ornamentation should wait until Advent — unless you put up your Christmas decorations in early November to greet the start of football season. It reminds me of a part of family history that shows how much the culture has changed. 

Eight decades ago, my sister Helen was born on Dec. 18, one week before Christmas. Mom and Dad decided to decorate the living room and deck our front porch with colored lights as a way of making her birthday more special. In later years, Dad fondly told of his amusement when neighbors came by, concerned that he was “rushing the season.”

Mary’s fiat echoes in homes throughout everyday life. Since parents are their children’s first and principal teachers, Abigail said, Mary’s fiat is “further mirrored in the mother who forgives her child again. In the father who works quietly to provide and joins his wife in helping their kids each week with their homework. In the widow who lights a candle alone. In the priest who approaches the altar with a steady heart.

“Mary’s fiat is heard when a toddler rearranges the Nativity scene. It is there, in a grandmother humming Silent Night while stirring the soup she made from scratch. The virgin’s fiat is in the chaos of Christmas morning, where wrapping paper flies, and grace sneaks in through a family’s laughter.”

I believe Mary’s fiat rings joyously when a newborn baby is looked on with love, parents gazing at their child as Mary and Joseph once did: the manger is quietly mirrored in hospital and living rooms.

“Mary’s fiat wasn’t merely a feeling, a whim,” Abigail continued. “It was a decision. A posture. A rhythm of obedience that doesn’t demand full understanding, only faith. So, whenever anyone, man or woman, boy or girl, faces a moral dilemma — a crossroads — and chooses trust over certainty, surrendering to God over personal control by saying, ‘Yes’ to God’s will, regardless of the cost, he or she echoes Mary’s courageous fiat.

“In a world that prizes control, Mary’s fiat is countercultural. It says: I don’t need to understand to obey. I don’t need to see the end to begin.”

Many of us, Catholics and not, dust off a Mary statuette in early December for Christmas creches. Then, we put her away again for another year. Maybe some are afraid to think about her in relation to her Son, but Mary’s fiat goes to the very heart of Christmas.

Echoes of Mary’s fiat are heard each time we say, “And blessed is the fruit of thy womb, Jesus.”

We see God’s fiat lux united to Mary’s fiat mihi. Both are united in Jesus: “through him was life, and this life was the light of the human race; the light shines in the darkness, and the darkness has not overcome it” (Jn 1:4-5).