I am an associate member of the Mission of the Immaculate Mediatrix (MIM) since spring 2013. Each day I say an act of consecration (which I really love!), written by St. Maximilian Kolbe:
Solemn Act of Consecration to the Immaculate
by St. Maximilian Mary Kolbe
O Immaculate, Queen of heaven and earth, Refuge of sinners and our most loving Mother, God has willed to entrust the entire order of mercy to you. I, an unworthy sinner, cast myself at your feet, humbly imploring you to take me with all that I am and have, wholly to yourself as your possession and property. Please make of me, of all my powers of soul and body, of my whole life, death , and eternity, whatever pleases you. If it pleases you, use all that I am and have without reserve, wholly to accomplish what has been said of you: “She will crush your head,” and “You alone have destroyed all heresies in the whole world.” Let me be a fit instrument in your immaculate and most merciful hands for introducing and increasing your glory to the maximum in all the many strayed and indifferent souls, and thus help extend as far as possible the blessed Kingdom of the Most Sacred Heart of Jesus. For, wherever you enter, you obtain the grace of conversion and sanctification, since it is through your hands that all graces come to us from the Most Sacred Heart of Jesus.
V. Allow me to praise you, O most holy Virgin.
R. Give me strength against your enemies.
St. Maximilian Kolbe writes about the phrase “You alone have destroyed all heresies in the whole world” (this phrase is from the Little Office of the Blessed Virgin Mary):
How can this be, for indeed heresies yet exist! Here Holy church in its prayers to the most Holy Mother of God speaks of the already accomplished destruction of heresies– all of them. […] Note it is a question of heresies. She does not destroy heretics. These she loves; she wants their conversion. It is her love towards them that prompts her to free them from heresy by destroying in them erroneous attitudes and convictions. […] How does she do this?
Mysterious are the marvelous ways of God’s providence and its activity in souls through the Immaculate. She enters the soul either through interior aspirations or through some circumstance. And when she enters a soul or if the doors of the soul open but a little, she comes to it to purify it of sins and vices, embellishes it with virtues and leads it to a fervent love. 
When reflecting on the Franciscan Order and its purpose, St. Maximilian exclaims:
“Through the Immaculate” (the spirit of the M.I.) we remain like an instrument in her hands, begging her to direct everything as she pleases. Acting thus we shall do as much as possible and in the quickest manner. We shall proclaim the Gospel with the greatest efficacy and to ever widening circles. Let her preach through us and in us. Let her make our life her own life. Let her live in us. […]
O Immaculate, Immaculate, Immaculate, Immaculate! How sweet, how delightful to a son’s heart is your holy name! How greatly it re-echoes in the soul; what a marvelous melody! The world as yet does not know you. Many know you only superficially. Grant that we may praise you, O holy Virgin! Give us strength against your enemies! 
 St. Maximilian Kolbe (SK 1170), as quoted in The Kolbe Reader, compiled and edited by Fr. Anselm W. Romb, OFM Conv., Marytown Press, Libertyville, Illinois (2007)
 ibid. (SK 991)