The Church has consistently recognised Mary as holy and immune from any sin or moral imperfection. The Council of Trent expresses this conviction by stating that no one "can avoid, in his whole life, every sin, even venial, except by virtue of a special privilege, as the Church holds with regard to the Blessed Virgin" (DS 1573). The possibility of sin does not even spare the Christian transformed and renewed by grace. This in fact does not preserve from all sin for life, unless, as the Tridentine Council states, a special privilege ensures such immunity from sin. This is what happened in Mary.
The Tridentine Council did not wish to define this privilege, it did, however, state that the Church strongly affirms it: 'Tenet', that is, it firmly believes it. This is a choice that, far from relegating this truth among pious beliefs or devotional opinions, confirms its character as solid doctrine, well present in the faith of the People of God. Moreover, this conviction is based on the grace attributed to Mary by the angel at the Annunciation. Calling her "full of grace", kecharitoméne, the angel recognises in her the woman endowed with a permanent perfection and fullness of holiness, without a shadow of guilt, or moral or spiritual imperfection.
Some early Church Fathers, not yet convinced of her perfect holiness, attributed moral imperfections or defects to Mary. Some recent authors have also adopted this position. But the Gospel texts cited to justify these views in no way allow the attribution of a sin, or even a moral imperfection, to the Mother of the Redeemer.
Jesus' reply to his mother at the age of 12: "Why did you seek me? Did you not know that I must be about my Father's business?" (Lk 2:49), has sometimes been interpreted as a veiled rebuke. Instead, a careful reading of the episode makes it clear that Jesus did not rebuke his mother and Joseph for looking for him, since they were responsible for watching over him.
Meeting Jesus after a painful search, Mary merely asks him the "why" of his behaviour: "Son, why have you done this to us?" (Lk 2:48). And Jesus answers with another "why", refraining from any reproach and referring to the mystery of his own divine filiation.
Not even the words spoken at Cana: "What have I to do with you, O woman? My hour has not yet come' (John 2:4), can be interpreted as a reproach. Faced with the probable discomfort that the lack of wine would have caused the couple, Mary turned to Jesus with simplicity, entrusting him with the problem. Jesus, although aware that he is the Messiah bound to obey only the Father's will, accedes to his Mother's implicit request. Above all, he responds to the Virgin's faith and thus begins the miracles, manifesting his glory.
Some have then interpreted in a negative sense the declaration made by Jesus when, at the beginning of his public life, Mary and relatives ask to see him. Referring to Jesus' reply to those who told him: "Your mother and your brothers are outside and wish to see you", the evangelist Luke offers us the key to understanding the story, which must be understood starting from Mary's intimate dispositions, quite different from those of the "brothers" (cf. Jn 7:5 ). Jesus replied: "My mother and my brothers are those who hear the Word of God and put it into practice" ( Lk 8, 21 ). In the story of the Annunciation, Luke showed how Mary was the model of listening to the Word of God and of generous docility. Interpreted from this perspective, the episode offers a great eulogy of Mary, who fulfilled the divine plan perfectly in her own life. Jesus' words, while opposing the brothers' attempt, extol Mary's faithfulness to God's will and the greatness of her motherhood, which she experienced not only physically but also spiritually.
In weaving this indirect praise, Jesus uses a particular method: he highlights the nobility of Mary's behaviour, in the light of more general statements, and better shows the Virgin's solidarity and closeness to humanity on the difficult path to holiness.
Lastly, the words: "Blessed rather are those who hear the word of God and keep it!" ( Lk 11, 28 ), pronounced by Jesus in response to the woman who declared his Mother blessed, far from casting doubt on Mary's personal perfection, emphasise her faithful fulfilment of the Word of God: this is how the Church has understood them, inserting this expression in the liturgical celebrations in honour of Mary.The Gospel text, in fact, suggests that with this statement Jesus wished to reveal precisely in intimate union with God, and in perfect adherence to the divine Word, the highest motive for his Mother's beatitude.
The special privilege granted by God to the 'all holy one' leads us to admire the wonders worked by grace in her life. It also reminds us that Mary was always and wholly the Lord's, and that no imperfection broke the perfect harmony between her and God.
Her earthly life, therefore, is characterised by the constant and sublime development of faith, hope and charity. For this reason, Mary is for believers the luminous sign of divine mercy and the sure guide to the lofty heights of evangelical perfection and holiness.
[Pope John Paul II, General Audience 19 June 1996]