Where does the First Fridays devotion come from?
This is not a pious novelty. It is anchored in Scripture. When Christ hung dead on the Cross, "one of the soldiers with a spear opened his side: and immediately there came out blood and water" (John 19:34, Douay-Rheims). The Fathers read that open side as the wellspring of the sacraments — the Church born from the wounded Heart. The devotion you keep on the First Friday is devotion to that literal, human Heart that bled for you.
The Catechism states it plainly: "the Sacred Heart of Jesus, pierced by our sins and for our salvation, is quite rightly considered the chief sign and symbol of that... love with which the divine Redeemer continually loves the eternal Father and all human beings" (CCC 478). And again: the Church "adores the incarnate Word and his Heart which, out of love for men, he allowed to be pierced by our sins" (CCC 2669). The Sacred Heart is the wound of God turned toward you. The First Friday is the day you answer it.
What Christ revealed to St. Margaret Mary Alacoque
Between 1673 and 1675, in the Visitation convent at Paray-le-Monial, France, Christ appeared to a Visitation nun, St. Margaret Mary Alacoque. He showed her His Heart, burning and crowned with thorns, and lamented that men returned His love with ingratitude. He asked for two things: reparation, and a Communion of reparation on the first Friday of the month.
Her testimony was not taken on private word alone. Her confessor, the Jesuit St. Claude de la Colombière, examined, believed, and propagated it; both are canonized saints of the Church (St. Claude canonized by St. John Paul II in 1992). The Church gave the devotion her approval, instituting the liturgical feast of the Sacred Heart. Pope Pius XII devoted an entire encyclical to it, Haurietis Aquas (1956), teaching that this devotion is "a worship of the love with which God through Jesus loves us and at the same time an exercise of our love." This is the Magisterium speaking — not sentiment.
What are the Twelve Promises and the Great Promise?
To St. Margaret Mary, Christ attached promises to devotion to His Sacred Heart. Twelve are traditionally enumerated and belong to the patrimony of the devotion: among them, that He will give the graces necessary for one's state of life, establish peace in homes, comfort the afflicted, bless the homes where the image of His Heart is exposed and honored, and bless every undertaking. These are best held as the traditional Catholic understanding of the devotion's fruits, received with trust, not as defined dogma.
The twelfth — the Great Promise — concerns the Nine First Fridays specifically. In St. Margaret Mary's own words: "I promise you in the excessive mercy of my Heart that my all-powerful love will grant to all those who receive Holy Communion on nine first Fridays of the month consecutively the grace of final repentance; they will not die under my displeasure, nor without receiving their sacraments, my divine Heart making itself their assured refuge at the last moment."
Read it soberly. This is not a magic charm or a guarantee that license is now safe. It is a promise of the grace of final repentance — that a man who makes these nine Communions in genuine love and faith will be given, at the hour of his death, the grace to turn to God. It presumes a heart that is actually seeking Christ, not gaming Him. Final perseverance is God's gift; here Christ pledges to give it. That is the allegiance the Sacred Heart asks, and the allegiance He rewards.
How to keep the Nine First Fridays — the man's checklist
The requirements are specific and worth getting exactly right. On the first Friday of nine consecutive months:
1. Receive Holy Communion. This is the heart of the devotion — a Communion of reparation. It must be worthy, meaning received in a state of grace. St. Paul warns that to receive unworthily is to be "guilty of the body and of the blood of the Lord" (1 Corinthians 11:27, Douay-Rheims). So if you carry mortal sin, you must go to Confession first; the universal custom is to confess within roughly eight days before or after the First Friday so that your Communion is worthy and your soul is clean.
2. Offer it in reparation. Make the intention — at least implicitly — to console the Sacred Heart and make amends for sins committed against His love, your own and the world's. Friday is already the Church's day of penance, kept in memory of the Lord's Passion; this devotion takes up that penitential character and aims it at the Heart.
3. Keep them consecutive. Nine first Fridays, nine months in a row, unbroken. If you miss one, the count resets and you begin again. That is not Christ being harsh — it is the simplest possible test of whether a man will keep faith for nine months running.
Concretely: put the first Friday of each month on your calendar now. Find the parish that offers a First Friday Mass — many add Adoration and Confession around it. Get to Confession this week. Show up Friday, receive, and offer it for the reparation of the Sacred Heart and for the grace of a holy death. Then do it eight more times. That is the whole devotion, and it will reorder your interior life around the altar.