The practice of consecration to Jesus through Mary was promoted extensively by the 17th century priest St. Louis de Montfort. In his book "True Devotion to Mary", St. Louis encourages every to make a formal act of consecration to Mary, so that through her, one can be consecrated to Jesus Christ. To "consecrate" ourselves to Mary means to entrust our entire lives fully to her, so that she can mould us, form us, nurture us, protect us, and make us become more and more like her Son, Jesus.
St. John Paul II stated that as a young seminarian he had read and reread Montfort many times and "understood that I could not exclude the Lord's Mother from my life without neglecting the will of God-Trinity". It was St. Louis de Montfort who influenced St. John Paul II's famous motto, "Totus Tuus, Maria", or "Totally Yours, Mary."
Below is the text of St. Louis de Montfort's Act of Consecration to Our Lady. It is best to recite this prayer daily. However, it is especially encouraged to make this Act of Consecration to her during some of the great feast days of Our Lady.
Act of Consecration to the Immaculate Heart of Mary (by St. Louis de Montfort)
I, (Name), a faithless sinner -
renew and ratify today in thy hands,
O Immaculate Mother,
the vows of my Baptism;
I renounce forever Satan,
his pomps and works;
and I give myself entirely to Jesus Christ,
the Incarnate Wisdom,
to carry my cross after Him
all the days of my life,
and to be more faihful to Him
than I have ever been before.
In the presence of all the heavenly court
I choose thee this day,
for my Mother and Mistress.
I deliver and consecrate to thee,
as thy slave, my body and soul,
my goods, both interior and exterior,
and even the value of all my good actions,
past, present and future;
leaving to thee the entire
and full right of disposing of me,
and all that belongs to me, without exception,
according to thy good pleasure,
for the greater glory of God,
in time and in eternity.