1) Although we receive the necessary graces for our salvation, we still need special graces to persevere. This is because the process of the decadence of a soul generally follows a pattern.
First, one commits acts of ingratitude that cause a retraction of grace. This causes the person in the state of grace to deteriorate slowly and stand in need of exceptional graces. When graces dwindle, one goes from one abuse to the next, until eventually falling into mortal sin.
2) Devotion to Our Lady is crucial in obtaining the necessary graces to save the soul from this process. We need an intercessor who supplements this gap with requests for additional graces, so that we might have sufficient graces for our salvation.
3) Our Lady obtains for us the graces necessary to attain salvation. The mere fact that we are devoted to her makes us pleasing to God Who is thus predisposed to answer our requests. However, human nature is so weak that we often abuse grace to such an extent that it is difficult to find those who practice sufficient fidelity to save themselves without Our Lady's intervention.
One might ask if this means that Our Lady is not the Mediatrix of all graces, but only of extraordinary graces. No, she also obtains the minimum of essential graces for us. However, our malice serves to demonstrate that we cannot persevere in the spiritual life without her full support.
Imagine a friend who is in a "state of grace," so to speak, in relation to you. In other words, he is a friend who depends completely on your kindness, and generally acts correctly toward you. However, although this friend does not commit grave faults against you, he nevertheless constantly commits small faults such as lack of courtesy, respect or affection. Of course, to the degree that he insists upon doing this, you gradually withdraw your friendship from him.
If he commits a grave fault, it is understandable that you severe your relationship with him.
This is a bit like the image of a sinner who, without losing the state of grace, almost inevitably, falls into mortal sin at a certain moment. To prevent this fall, the intercession of Our Lady is greatly needed. It is not only greatly needed, but indispensable since after a mortal sin, a person has no claim to obtain forgiveness.
Even if he were to repent, it is doubtful that God would give Heaven to a person in this state of soul without subjecting him to grave trials as a punishment for his attitude.
4) Some people suppose that death comes as an accident, a disaster outside the ways of Providence, and that God has nothing to do with death.
Man walks along the ways of the spiritual life as he so pleases, and then all of a sudden death comes and interrupts God's plans and the development of his soul. In fact, it is nothing like this at all. No hair drops from our head without God allowing it. Everything is proportional to the orientation of our spiritual life.
In fact, the moment of our death is perfectly chosen with regard to our sins and merits. Without an intercessor with the merits of Our Lady, it would be impossible to remain in the state of grace.
Imagine that a friend commits several small faults toward you, but nothing atrocious. All of a sudden he shows up asking you for a gift. Would you be ready and willing to give it? Depending on the situation, you might refuse any request on his part.
5) Our spiritual life is not a plateau next to an abyss. It is an inclined ramp, in the middle of which is a line that separates the state of grace from mortal sin. When someone is on the upper part of this ramp, he can go down without falling into mortal sin.
When a person on the upper part of the ramp commits an infidelity, God normally diminishes His graces; and with the dwindling of grace a person can fall into such a state of destitution as to be reduced to strictly indispensable grace.
When one says that venial sin leads to mortal sin, it does not mean that man lacks the sufficient grace not to fall, but that he all too often does not correspond to grace and thus falls. Human nature has a very strong penchant to abuse grace.
However, in each concrete case, man has the will to react. Man can only obtain all the necessary and opportune graces not to fall however, if he has recourse to Our Lady. And that is why we need Our Lady.
The preceding text is adapted from a lecture given by Prof. Plinio Corrêa de Oliveira. It has been translated and edited for publication without his revision. –Ed.