The Five First Saturdays devotion is one of the principal points of the Fatima message. It centres on the urgent need for mankind to offer reparation and expiate for the many injuries that the Immaculate Heart of Mary suffers from the hands of both an impious and indifferent mankind.
In December of 1925, Our Lady appeared to Sister Lucia, giving her the following guarantee of salvation for those who complete the First Five Saturdays Devotion
