I have already said that this devotion consists in performing all our actions with Mary, in Mary, through Mary, and for Mary.
It is not enough to give ourselves just once as a slave to Jesus through Mary; nor is it enough to renew that consecration once a month or once a week. That alone would make it just a passing devotion and would not raise the soul to the level of holiness which it is capable of reaching. It is easy to enroll in a confraternity; easy to undertake this devotion, and say every day the few vocal prayers prescribed. The chief difficulty is to enter into its spirit, which requires an interior dependence on Mary, and effectively becoming her slave and the slave of Jesus through her. I have met many people who with admirable zeal have set about practising exteriorly this holy slavery of Jesus and Mary, but I have met only a few who have caught its interior spirit, and fewer still who have persevered in it.
1. The essential practice of this devotion is to perform all our actions with Mary. This means that we must take her as the accomplished model for all we have to do.
Before undertaking anything, we must forget self and abandon our own views. We must consider ourselves as a mere nothing before God, as being personally incapable of doing anything supernaturally worthwhile or anything conducive to our salvation. We must have habitual recourse to our Lady, becoming one with her and adopting her intentions, even though they are unknown to us. Through Mary we must adopt the intentions of Jesus. In other words, we must become an instrument in Mary's hands for her to act in us and do with us what she pleases, for the greater glory of her Son; and through Jesus for the greater glory of the Father. In this way , we pursue our interior life and make spiritual progress only in dependence on Mary.
Act in Mary
2. We must always act in Mary, that is to say, we must gradually acquire the habit of recollecting ourselves interiorly and so form within us an idea or a spiritual image of Mary. She must become, as it were, an Oratory for the soul where we offer up our prayers to God without fear of being ignored. She will be as a Tower of David for us where we can seek safety from all our enemies. She will be a burning lamp lighting up our inmost soul and inflaming us with love for God. She will be a sacred place of repose where we can contemplate God in her company. Finally Mary will be the only means we will use in going to God, and she will become our intercessor for everything we need. When we pray we will pray in Mary. When we receive Jesus in Holy Communion we will place him in Mary for him to take his delight in her. If we do anything at all, it will be in Mary, and in this way Mary will help us to forget self everywhere and in all things.
Act Through Mary
3. We must never go to our Lord except through Mary, using her intercession and good standing with him. We must never be without her when praying to Jesus.
4. We must perform all our actions for Mary, which means that as slaves of this noble Queen we will work only for her, promoting her interests and her high renown, and making this the first aim in all our acts, while the glory of God will always be our final end. In everything we must renounce self- love because more often than not, without our being aware of it, selfishness sets itself up as the end of all we work for. We should often repeat from the depths of our heart: "Dear Mother, it is to please you that I go here or there, that I do this or that, that I suffer this pain or this injury."
Beware, chosen soul, of thinking that it is more perfect to direct your work and intention straight to Jesus or straight to God. Without Mary, your work and your intention will be of little value. But if you go to God through Mary, your work will become Mary's work, and consequently will be most noble and most worthy of God.
Again, beware of doing violence to yourself, endeavouring to experience pleasure in your prayers and good deeds. Pray and act always with something of that pure faith which Mary showed when on earth, and which she will share with you as time goes on. Poor little slave, let your sovereign Queen enjoy the clear sight of God, the raptures, delights, satisfactions and riches of heaven. Content yourself with a pure faith, which is accompanied by repugnance, distractions, weariness and dryness. Let your prayer be: "To whatever Mary my Queen does in heaven, I say Amen, so be it." We cannot do better than this for the time being.
Should you not savour immediately the sweet presence of the Blessed Virgin within you, take great care not to torment yourself. For this is a grace not given to everyone, and even when God in his great mercy favours a soul with this grace, it remains none the less very easy to lose it, except when the soul has become permanently aware of it through the habit of recollection. But should this misfortune happen to you, go back calmly to your sovereign Queen and make amends to her.