First, Mary uniquely shared in the work of Jesus to redeem the human family, both by giving Jesus his body, the very instrument of Redemption (cf. Lk. 1:38; Heb. 10:10), and by suffering with Him at Calvary in a way unparalleled by another other creature (cf. Jn. 19:25-27). For this extraordinary role with Jesus in saving souls, Mary has been called the “Co-redemptrix” in the Church since the 14th century. Fear not—“co” means “with” not “equal.” Mary’s not a goddess on a level or equality with Jesus. She is the unique immaculate human co-redeemer with Jesus, just as every Christian is called to be a “co-redeemer in Christ,” to use the expression of Bl. John Paul II.
Secondly, Mary nurtures us in the order of grace by distributing the graces obtained at Calvary to the human family through her role as the Mediatrix of all graces. The papal Magisterium of the last two centuries has consistently taught this Marian role, and Pope Benedict XVI Emeritus published this same title on the day he announced his resignation (Feb. 11, 2013). The Wedding of Cana (Jn. 2:5) reveals to us what the Second Vatican Council teaches us: that the Mother of Jesus “intercedes for the gifts of eternal life” (LG 62).
Thirdly, Mary, as Spiritual Mother, pleads for us before the throne of Christ the King as our Advocate. Her most ancient title (from the second century), Our Lady’s role as Advocate simply confirms that this Mother intercedes for our wants and needs with a maternal perseverance and power beyond that of any of the other saints.