FEAST OF THE IMMACULATE HEART OF THE BLESSED VIRGIN MARY
Why devotion to the Immaculate Heart of Mary?
“The world needs love, . . . True, authentic love. And in the Immaculate Heart of Mary we see what true love should be.
“Once again let us go to the source: The Message of Fatima, the whole revelation of the Heart of Mary, all Her words and Her attitude, a new formulation of the Evangelic Message.
“No one among pure creatures loved as She did.
“She is the . . . Pattern of love to God and to neighbor.
“Through Her, through Her Immaculate Heart of Mary, we sweep up more directly with Jesus to the Father. With Her we learn how to love. What more admirable school of love than Hers!
“The devotion to the Immaculate Heart of Mary is then, first of all, a lesson and school of love, of charity towards God and towards our neighbor, which should manifest itself in the fulfillment of all our daily duties of life.”
--V. Rev. Joseph Galamba de Oliveira
Canon, Diocese of Leiria-Fatima
[Excerpted from p. 154, A Heart for All, AMI Press]
Historically, devotion to the Heart of Mary can be traced to the twelfth century with such writers as St. Anselm ( d. 1109 ) and St. Bernard of Clairvaux ( d. 1153 ) who are considered as some of the most influential writers in Marian devotion. St. Bernardine of Siena ( 1380- 1444) has been called the Doctor of the Heart of Mary due to his writings on Mary's heart. He wrote, "from her heart, as from a furnace of Divine Love, the Blessed Virgin spoke the words of the most ardent love." St. John Eudes ( 1601 -1680 ) helped by his writings to begin a renewal in this devotion. Both Pope Leo XIII and Pope St. Pius X called him, "the father, Doctor, and Apostle of the liturgical cult of the Sacred Hearts of Jesus and Mary." Even two decades before the first liturgical celebrations in honor of the Heart of Jesus, St. John Eudes and his followers observed February 8th as the feast of the Heart of Mary as early as 1643. Pope Pius VII ( d. 1823 ) extended its celebration to any diocese or congregation requesting it.
Devotion to Mary's Heart has a greater flowering following the manifestation of the Miraculous Medal to St. Catherine Laboure in 1830 and the Appearances of' Our Lady in Fatima. From May 13 to October 13, 1917, our Blessed Mother Mary appeared to three children, Jacinta and Francisco Marto and their cousin Lucia DosSantos in Fatima, Portugal. On July 13th, she told them: "to save poor sinners, God wishes to establish in the world devotion to my Immaculate Heart." The entire Fatima message is one of prayer, penance and making sacrifices and reparation to God for the many offenses against Him.
Mary asked the children to pray the Rosary daily for the conversion of sinners and asked for devotion to her Immaculate Heart. She asked for prayer, penance and that Russia be consecrated to her Immaculate Heart. She also spoke of observing the first Saturdays of each month by going to confession and receiving Holy Communion to make reparation to the Hearts of Jesus and Mary.
Pope Paul IV & Lucia at Fatima
Pope Paul IV, who sent a Golden Rose to Fatima and then published “Signam Magnam”, "Letter on the Blessed Virgin Mary", upon his visit there in 1967 stated:
“May the Immaculate Heart of Mary shine before the eyes of all Christians as the model of perfect love toward God and toward our fellow beings; may it lead them toward the Holy Sacraments by virtue of which souls are cleansed from the stains of sin and are preserved from it. May it also stimulate them to make reparation for the innumerable offenses against the Divine Majesty. Lastly, may it shine like a banner of unity and a spur to perfect the bonds of brotherhood among all Christians in the bosom of the one Church of Jesus Christ, which "taught by the Holy Spirit, honors her with filial affection and piety as a most beloved mother." 
Since the 25th anniversary is recalled this year of the solemn consecration of the Church and of mankind to Mary, the Mother of God, and to her Immaculate Heart, by our predecessor of venerated memory, Pius XII, on Oct. 31, 1942 on the occasion of the broadcast message to the Portuguese nation  -- a consecration which we ourself have renewed on Nov. 21, 1964  -- we exhort all the sons of the Church to renew personally their consecration to the Immaculate Heart of the Mother of the Church and to bring alive this most noble act of veneration through a life ever more consonant with the divine will  and in a spirit of filial service and of devout imitation of their heavenly Queen."
Letter on the Blessed Virgin Mary
His Holiness Pope Paul VI
Promulgated on May 13, 1967
Today as we remember the Immaculate Heart of Mary, following the great Feast of the Sacred Heart of Jesus, Two Hearts that are always joined as One, let us re-consecrate ourselves to these Two Hearts and join our hearts to Theirs . . .