The First Friday’s devotion should be done with the intention of offering reparation to the Sacred Heart of Jesus for all insults, sins, and offenses committed against Him. This devotion arises from the private revelations of Jesus to St. Margaret Mary Alacoque (1647-1690). One of the promises Jesus made to St. Margaret Mary is as follows:
I promise you in the excessive mercy of My Heart that My all-powerful love will grant to those who receive Holy Communion on the First Fridays in nine consecutive months the grace of final perseverance; they shall not die in My disgrace, nor without receiving their sacraments. My divine Heart shall be their safe refuge in this last moment.
Jesus made the following 12 promises to St. Margaret Mary in favor of those who consecrate to the Sacred Heart, in a spirit of reparation, the First Friday of each month.
1. I will give them all the graces necessary in their state of life.
2. I will establish peace in their homes.
3. I will comfort them in all their afflictions.
4. I will be their secure refuge during life, and above all, in death.
5. I will bestow abundant blessings upon all their undertakings.
6. Sinners will find in My Heart the source and infinite ocean of mercy.
7. Lukewarm souls shall become fervent.
8. Fervent souls shall quickly mount to high perfection.
9. I will bless every place in which an image of My Heart is exposed and honored.
10. I will give to priests the gift of touching the most hardened hearts.
11. Those who shall promote this devotion shall have their names written in My Heart.
12. 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 the First Fridays in nine consecutive months the grace of final perseverance; they shall not die in My disgrace, nor without receiving their sacraments. My divine Heart shall be their safe refuge in this last moment.
The Church grants a Plenary indulgence to those who attend Mass and receive Communion in honor of The Sacred Heart of Jesus on the First Friday of each month for nine (9) consecutive months. To acquire a plenary indulgence, it is necessary to perform the work to which the indulgence is attached and to fulfill the following three conditions: 1. sacramental confession, 2. Eucharistic Communion, and; 3. prayer for the intention of the Sovereign Pontiff.