Courtesy of Cardinal Ratzinger. After explaining that if Jesus is the seed placed in the soil, then Mary is the soil, Ratzinger makes explains why we need the Marian mystery of the Church (emphases mine):
In my opinion, the connection between the mystery of Christ and the mystery of Mary suggested to us by today’s readings is very important in our age of activism, in which the Western mentality has evolved to the extreme. For in today’s intellectual climate, only the masculine principle counts. And that means doing, achieving results, actively planning and producing the world oneself, refusing to wait for anything upon which one would thereby become dependent, relying rather, solely on one’s own abilities. It is, I believe, no coincidence, given our Western, masculine mentality, that we have increasingly separated Christ from his Mother, without grasping that Mary’s motherhood might have some significance for theology and faith. This attitude characterizes our whole approach to the Church. We treat the Church almost like some technological device that we plan and make with enormous cleverness and expenditure of energy. Then we are surprised when we experience the truth of what Saint Louis-Marie Grignon de Montfort once remarked, paraphrasing the words of the prophet Haggai, when he said, ‘You do much, but nothing come of it’ (Hag 1.6)! When making becomes autonomous, the things we cannot make but that are alive and need time to mature can no longer survive.
What we need, then is to abandon this one-sided, Western activistic outlook, lest we degrade the Church to a product of our creation and design. The Church is not a manufactured item; she is, rather the living seed of God that must be allowed to grow and ripen. This is why the Church needs the Marian mystery; this is why the Church herself is a Marian mystery. There can be fruitfulness in the Church only when she has this character, when she becomes holy soil for the Word. We must retrieve the symbol of the fruitful soil; we must once more become waiting, inwardly recollected people who in the depth of prayer, longing, and faith give the Word room to grow.”
(Ratzinger/von Balthasar, Mary:The Church at the Source, pp. 16-17)