How does it work?
An excerpt from ‘Totus Tuus’
From Blessed John Paul II:“When the fullness of time had come, God sent forth his Son, born of woman” (Gal 4:4). The fullness of time coincides with the mystery of the Incarnation of the Word, of the Son who is of one being with the Father, and with the mystery of the Redemption of the world. In this passage, Saint Paul emphasizes that the Son of God was born of woman, born under the Law, and came into the world in order to redeem all who were under the Law, so that they might receive adoption as sons and daughters.
And he adds: “Because you are sons, God has sent the Spirit of his Son into our hearts, crying ‘Abba! Father!’” His conclusion is truly comforting: “So through God you are no longer a slave but a son, and if a son then an heir” (Gal 4:6-7). Paul’s presentation of the mystery of the Incarnation contains the revelation of the mystery of the Trinity and the continuation of the Son’s mission in the mission of the Holy Spirit.
The Incarnation of the Son of God, his conception and birth, is the prerequisite for the sending of the Holy Spirit. This text of Saint Paul thus allows the fullness of the mystery of the Redemptive Incarnation to shine forth (NMI, 1).
[Mary] is the way that leads to Christ: indeed, she who “at the message of the angel received the Word of God in her heart and in her body” (LG, 53) shows us how to receive into our lives the Son come down from heaven, teaching us to make Jesus the center and the supreme “law” of our existence. (Gen. Aud., January 10, 1996)