In its dogmatic Constitution on the Church, Lumen Gentium, the Vatican II Council linked Mary's cooperation in the Redemption to her indissoluble union with Jesus. From Christ’s and Mary’s indissoluble union decreed by God the Father flows the doctrine of Mary's collaboration in salvation: Mary depends on Christ but she acts with Christ, being united to Him by an indissoluble bond.
- "Wishing in His supreme goodness and wisdom to effect the redemption of the world..." (Lumen Gentium 52).
- Mary is "united to Him by a close and indissoluble tie" (Lumen Gentium 53).
Cooperation means "being with" in an active, operative form. Mary was present with Jesus and she is present with the Church, because where Jesus is present and born, Mary is there. She is therefore especially present during the Eucharistic celebration and at Baptism.
Anthropology is another very important emphasis of the Vatican II Council: Mary gave her free consent. And this free consent was necessary. Mary's "Yes" is the condition of the Incarnation. She is the Mother of God, indeed, but more specifically she is the Mother of God the Savior. She says "Yes" to God who saves, and to the Incarnation in its saving mission.
François Breynaert, testimariani.net