I’ll close by saying that if you “Get Mary” you “Get Catholicism.” Mary represents everything that Catholicism is: sacraments, incarnation, sanctity, matrimony, celibacy, prayer, silence, love, charity, faith and works, and even the synergy of the divine work within human vessels.I have long thought this but not been able to express it this well. Seeing that the church father's had a devotion to Mary was on the surface just one area where they disagreed with protestants. But it was more than that. I felt that it showed a deep Catholicism.
I see that in the modern church as well. When I try to sort out liberal Catholics from those that understand the faith I have learned that Marian devotion is a very good sign. It is related to the concept of spiritual motherhood. If you accept Mary as a mother you will accept the church as a mother and vise versa. Even though the church does more mothering. The church gives us spiritual food in the Eucharist, she nurses us back to spiritual health when we sin, she makes the rules for the house, etc. Still Mary is mother in other ways. She is what we want to be when we grow up. She is in heaven. She is free from all sin, both original and actual. She blesses the world by mediating God's grace.
The other parallel is both Mary and the church offer the sacrifice of Jesus on our behalf. Mary did it at the cross and the church does it at the mass. The idea that a sacrifice must be offered willingly to be effective. That we are not able to do that. We need a special grace to do that. So the grace of the immaculate conception was needed at the cross. The grace of an immaculately conceived church is needed today.
It boils down to what a protestant would call Sola Christo. That is the sufficiency of Christ. But that is not accurate. Because Christ provided us a church and He provided us with His mother. So Christ is not lacking. Really what is lacking is us. We need help that goes beyond letting Jesus into our hearts. Not because Jesus lacks anything but because we need to be more fully transformed. We need to know what that looks like before we can say Yes to it. Before we can go out and live it. That has to be constant. Like the difference between a wedding vow and a marriage.