8. With her distinctive doctrine and unmistakable style, Therese appears as an authentic teacher of faith and the Christian life. In her writings, as in the saying of the Holy Fathers, is found that lifegiving presence of Catholic tradition whose riches, as the Second Vatican Council again says, "are poured out in the practice and life of the Church, in her belief and prayer" (Die Verbum, n. 8).
If considered in its literary genre, corresponding to her education and culture, and if evaluated according to the particular circumstances of her era, the doctrine of Therese of Lisieux appears in providential harmony with the Church's most authentic tradition, both for its confession of the Catholic faith and for its promotion of the most genuine spiritual life, presented to all the faithful in a living, accessible language.
She has made the Gospel shine appealingly in our time; she had the mission of making the Church, the Mystical Body of Christ, known and loved; she helped to heal souls of the rigors and fears of Jansenism, which tended to stress God's justice rather than his divine mercy. In God's mercy she contemplated and adored all the divine perfections, because "even his justice (and perhaps even more so than the other perfections) seems to me clothed in love" (Ms A, 83v). Thus she became a living icon of that God who, according to the Church's prayer, "shows his almighty power in his mercy and forgiveness" (cf. Roman Missal, Opening prayer, 26th Sunday in Ordinary Time).
Even though Therese does not have a true and proper doctrinal corpus, nevertheless a particular radiance of doctrine shines forth from her writings which, as if by a charism of the Holy Spirit, grasp the very heart of the message of Revelation in a fresh and original vision, presenting a teaching of eminent quality.
The core of her message is actually the mystery itself of God-Love, of the Triune God, infinitely perfect in himself. If genuine Christian spiritual experience should conform to the revealed truths in which God communicates himself and the mystery of his will (cf. Dei Verbum, n. 2), it must be said that Therese experienced divine revelation, going so far as to contemplate the fundamental truths of our faith united in the mystery of Trinitarian life. At the summit, as the source and goal, is the merciful love of the three Divine Persons, as she expresses it, especially in her Act of Oblation to Merciful Love. At the root, on the subject's part, is the experience of being the Father's adoptive children in Jesus; this is the most authentic meaning of spiritual childhood, that is, the experience of divine filiation, under the movement of the Holy Spirit. At the root again, and standing before us, is our neighbor, others, for whose salvation we must collaborate with and in Jesus, with the same merciful love as his.
Through spiritual childhood one experiences that everything comes from God, returns to him and abides in him, for the salvation of all, in a mystery of merciful love. Such is the doctrinal message taught and lived by this Saint.
As it was for the Church's Saints in every age, so also for her, in her spiritual experience Christ is the center and fullness of Revelation.
Therese knew Jesus, loved him and made him loved with the passion of a bride. She penetrated the mysteries of his infancy, the words of his Gospel, the passion of the suffering Servant engraved on his holy Face, in the splendor of his glorious life, in his Eucharistic presence. She sang of all the expressions of Christ's divine charity, as they are presented in the Gospel (cf. PN 24, Jesus, mon Bien-Aime, rappelle-toi!).
Therese received particular light on the reality of Christ's Mystical Body, on the variety of its charisms, gifts of the Holy Spirit, on the eminent power of love, which in a way is the very heart of the Church, where she found her vocation as a contemplative and missionary (cf. Ms B, 2r-3v).
Lastly, among the most original chapters of her spiritual doctrine we must recall Therese's wise delving into the mystery and journey of the Virgin Mary, achieving results very close to the doctrine of the Second Vatican Council in chapter eight of the Constitution Lumen gentium and to what I myself taught in the Encyclical Letter Redemptoris Mater of 25 March 1987.
excerpted from "Divini Amoris Scientia," the Apostolic Letter of Pope John Paul II declaring St. Therese of Lisieux a Doctor of the Church.