The First Friday Devotion to the Sacred Heart of Jesus is based on a promise made by our Lord Jesus Christ during an Apparition to St. Margaret Mary Alacoque. This promise was implicitly approved by the Church in the 1920 canonization of St. Margaret Mary.

The 12 Promises are contained in a letter written in May 1688 by St. Margaret Mary to Mother Saumaise:

“On a Friday during Holy Communion, [Our Lord] said these words, I promise you in the excessive mercy of My Heart that Its 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 or without receiving their Sacraments, My Divine Heart making Itself their assured refuge at the last moment.”

The Promises of the Sacred Heart of Jesus to St. Margaret Mary Alacoque:

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 their afflictions.”
4. “I will be their secure refuge during life, and above all in death.”
5. “I will pour abundant blessings upon all their undertakings.”
6. “Sinners shall find in My Heart the source and the infinite ocean of mercy.”
7. “Tepid souls shall grow fervent.”
8. “Fervent souls shall quickly mount to high perfection.”
9. “I will bless every place where a picture of My Heart shall be set up 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, never to be effaced.”
12. “The all-powerful love of my heart will grant to all those who shall receive communion on the first Friday of nine consecutive months the grace of final repentance.”