In the fifth section of the first part, when analyzing the essence of the Cursillos, we considered how the doctrine that is communicated in the Cursillo is the doctrine of the Mystical Body of Christ; a doctrine based on a life that supposes a rediscovery of Christianity in which the Person of Jesus Christ is the centre. It is a living and dynamic presentation, a communication of life with an incorporated invitation to participate in that life.
We saw in the same section that the Cursillo tries to instil truths whose fundamental nucleus is Christ Jesus and His grace, with a vision that joins together the fundamental truths of the Catholic Faith.
Advancing in the specific doctrine that is taught in the Cursillos, Mgr. Hervàs gives a clear, defined answer:
The doctrine that is taught in the Cursillos is solid and true, according to the doctrine of Saint Thomas and the traditional scholastic method. The whole life of the Cursillos is developed with the eyes and ears attentive to the lessons and norms of the Roman Pontiffs.
In the same Pastoral Letter, speaking about the contents, he will indicate that:
It is not a new doctrine, but is however new in the way and the order in which it is proposed and taught. What is taught, as we said, is no more than what the Holy Catholic, Apostolic, Roman Church teaches and proposes. The central nucleus is the doctrine of the Mystical Body of Christ. It follows the method of Saint Thomas Aquinas in Philosophy and Theology, in accordance with the best authors used in the Seminaries and ecclesiastical Universities.
Later he remarks again that the doctrinal key of the Cursillos is in the doctrine of the Mystical Body and the Communion of Saints, and this is confirmed in the four points that we reproduce in the following outline:
A) Jesus Christ, Head of the Mystical Body.
B) Grace, the living sap of the Mystical Body of Christ.
C) The Holy Spirit, soul of the Mystical Body of Christ.
D) The Church and its sacred teaching.
The Cursillo is profoundly Christ-centred in the doctrine it preaches, also in the call to conversion it proclaims and in the plan of life that it proposes with a view to perseverance. The centre of the Cursillo is the Person of Jesus, mystically present in its members through faith, grace and charity. He is also present in a real and substantial way in the Holy Eucharist....
The Person of Jesus will be preached intensely, presented with liveliness as God and as man who seeks and offers a personal relationship with man, with each specific man, who comes to renew his life totally and to open a horizon of contribution in the transformation of the world. This Jesus is present in the environment, and above all, the tabernacle will be a constant reference point during the Cursillo, not only in the Eucharistic Celebrations, but also in the individual and community visits.
The second doctrinal point is the presentation of Grace as the vital sap of the life of the Church. A life that flows from Christ as Head to the members of his Mystical Body, and which must be valued as a magnificent gift. For that reason the Cursillo teaches the love and esteem of divine grace as a gift of the Father, by the Son in the Holy Spirit; the true wealth of the redeemed (…) which acquisition, conservation, increase and diffusion will be the great ideal of life as a whole .
Grace is a gift of God that makes us his friends, his children, which places us in a new life; it is, in reality, a participation of divine life. It is something so great and so new – even though it has always been a truth - that although the Person of Jesus Christ constitutes the centre of the Cursillo, the central lesson of the Cursillo is sanctifying Grace; everything revolves around this great truth. However, a complete treatment is not given as is well understood. This formative task is completed in the Postcursillo. The definition of grace is explained; the concept of the supernatural world is exposed; the criterion that the supernatural orientation of man is the only really true one….
The Holy Spirit as soul of the Mystical Body of Christ constitutes the third doctrinal point of the Cursillo, for this reason it teaches a lively devotion and frequent invocation of the Holy Spirit, who vivifies, guides, directs and perfects the Church and souls.
The Holy Spirit, soul of the Mystical Body, is the great stranger and many Christians have a minimal and elementary notion of His existence. However, the mystery of Christ cannot be understood unless we possess the light and guidance of the Holy Spirit. For that reason it is so important to know his action in the Church and in each individual person. His influence is evident throughout the history of the Church in all time, although certainly in the beginning it was more evident than at the present time.
Christ sustains the whole Body and each individual member by the Holy Spirit, who makes us adopted children of God, which is the beginning of the unity of the members with Christ the Head and within each other.
Knowledge of the Holy Spirit is essential in doctrinal formation, and personal contact with Him is essential in Christian life, the third Person of the Holy Trinity. He is also the beginning of supernatural life, and for that reason in the Cursillos in Christianity the Christian is taught to hold in special esteem the devotion to the Holy Spirit, to invoke Him, to support with liturgical prayer, with concentration and faith, when inaugurating the Cursillo and at the beginning of each one of the main acts. Encouragement is also given to the participants to continue this devotion during the daily tasks of existence and in the important moments of life.
The fourth doctrinal point deals with the Church and its teachings. It is expressed in a single paragraph, long and with one theme, that does not really reflect the doctrinal orientation given in the Cursillo on the Church, but rather a loyalty to the hierarchy of the Church. It says thus: Knowledge, love and generous service to the Holy Church, external, visible and hierarchic, which is expressed in an unshakeable fidelity and love of the Pope, Vicar of Jesus Christ and visible Head of the universal Church; in the joyful and sincere acceptance of its lessons and directives, that illuminate the minds and guide the activities of Catholics in all times and all parts of the Earth. Submission, sincere and practical love to the diocesan Bishop, in intimate communion with the Apostolic See, placed by the Holy Spirit to govern the Church of God in each part of the Christian world. Knowledge of the mission and dignity of the catholic priest; consideration and cordial esteem for them, that perhaps begins in a human friendship in the days of the Cursillo, before being transformed afterwards into an incipient and smooth spiritual direction, that ordinarily will continue progressing, invigorating and extending gradually later.
Later, in a section which deals at length with point b, Grace, from the perspective of the communion of life that Christ as Head gives his members, completes the previous vision that seemed only to associate hierarchy and teaching with the idea of a common and unique life, and of the communion and solidarity of interests in that living organism that is the Mystical Body of Christ: By virtue of that common life (...) the Christian becomes aware of the solidarity of interests of the Mystical Body and he feels so united with his brothers that he will act with the conviction that if he lives in grace, he will elevate others; if he lives in sin, he will reduce the vitality and strength of the Mystical Body of Jesus Christ.
In conclusion, we can affirm that the information offered by the oldest and most representative books about the beginnings of the Cursillos and their doctrinal bases, lead us to the conclusion that the doctrine taught by them is Thomist in accordance with the traditional scholastic method. The doctrinal contents are to be found mainly in the "Mystical Talks" and the Meditations. These are composed from works used in those years such as manuals and books of spirituality, whose authors are Aramí, Lennerz, Terrien, Tanquerey and Toth.
From the totality of truths of Catholic Christian dogma, grace is taken to be the doctrinal axis, from the perspective of the Mystical Body. This doctrine is articulated in four points: Christ, Grace, the Holy Spirit and the Church.
 CCIRC, p. 163.
 Ibid., pp. 174-175.
 Cf. Ibid., p. 176.
 Cf. Ibid., pp. 176-178.
 Ibid. pp.176-177; in CPSNE, attention is drawn to the fact that Christ is the central point of the contents of the message proclaimed in the Cursillo, even culminating in the affirmation that a Cursillo is the preaching of a living and personal Christ, p.59.
 Ibid., pp. 177-178.
 Ibid., p. 186.
 Ibid., p. 178.
 Cf. Ibid., pp. 222-229.
 Cf. MC, nn. 25-26.
 CCIRC, p. 232.
 Ibid., p, 178.
 Ibid., p. 188.
 Cf. note 105 of this work