Saint Margaret Mary was French, and, as a child, was sickly. Once she made a vow to the Blessed Virgin to become a nun, she was healed. According to an article from Aquinas Goods, she was not surprised when she received the visions; she assumed everyone had them. She was assigned the task of devotion to the Sacred Heart of Jesus.
Saint Margaret Mary lived in a time when going to Communion wasn't a weekly occurrence, as it is now for Catholics. So, going to Communion frequently was huge.
In order to be endowed with the below promises, one must, for 9 consecutive First Fridays, attend Mass and receive Communion.
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 bestow a large blessing 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 blotted out."
12. "I promise thee in the excessive mercy of My Heart that My all-powerful love will grant to all those who communicate on the First Friday in nine consecutive months, the grace of final penitence; they shall not die in My disgrace nor without receiving the Sacraments; My Divine heart shall be their safe refuge in this last moment."