From www.consecration.com, website of the Militia of the Immaculata:
Consecration means setting yourself aside for service to God. The Church has always advocated consecrating yourself to Jesus Christ through the Blessed Virgin, the perfect model of discipleship.
Marian consecration is a formal act of self-giving that does not stop at Mary, but is Christ-directed. It is really consecration to Jesus. The MI's mission is "To Lead Every Individual With Mary to the Most Sacred Heart of Jesus."
By joining the MI, members become willing instruments of Our Lady, the woman foreshadowed in Genesis 3:15. She leads them to personal sanctification, the conversion of Church opponents and ultimately the universal reign of the Sacred Heart of Jesus.
The spirit of the MI is the spirit of continual conversion. Not everyone who enrolls as a member understands perfectly in the beginning the power of this consecration. But when lived in the spirit of willingness and humility, the Immaculata will elevate our natural gifts and inspire us to holiness and fruitful service within the Church.
As Jesus said to those who would stand up and follow him: "Even greater things than these will you do."
The Militia of the Immaculata was founded by Saint Maximilian Kolbe on October 16, 1917.
In 1941, the Nazis imprisoned Father Maximilian in the Auschwitz death camp. There he offered his life for another prisoner and was condemned to slow death in a starvation bunker. On August 14, 1941, his impatient captors ended his life with a fatal injection. Pope John Paul II canonized Maximilian as a "martyr of charity" in 1982. St. Maximilian Kolbe is considered a patron of journalists, families, prisoners, the pro-life movement and the chemically addicted.
It is traditional in the MI movement to choose a Marian feastday on which to dedicate yourself to Jesus through Mary. Sunday is the Feast of Mary, the Mother of God. There are many Marian feasts peppered throughout the church year.
January 1 - Solemnity of Mary, Mother of God
January 8 - Our Lady of Prompt Succor
February 2 - Presentation of the Lord
February 11- Our Lady of Lourdes
March 25 - Annunciation
May 31 - Visitation
June 27 - Our Mother of Perpetual Help
July 16 - Our Lady of Mount Carmel
August 15 - Assumption
August 22 - Queenship of Mary
September 8 - Birth of Mary
September 12 - The Most Holy Name of Mary
September 15 - Our Lady of Sorrows
September 24 - Our Lady of Walsingham, England
October 7 - Our Lady of the Rosary
November 21 - Presentation of the Blessed Virgin Mary
December 8 - Immaculate Conception
December 12 - Our Lady of Guadalupe