The foundation of the Church’s teaching on mortification is the fact that Jesus Christ, out of love for mankind, voluntarily accepted suffering and death (his “passion”) as the means to redeem the world from sin. Christians are called to emulate Jesus’ great love and, among other things, join him in his redemptive suffering. Thus Christians are called to “die to themselves.” The Church mandates certain mortifications – fasting and abstinence from meat – as Lenten penances. Some people in the history of the Church have felt called to undertake greater sacrifices, such as frequent fasting or using a hairshirt, cilice, or discipline, as can be seen in the lives of many of those explicitly recognized by the Church as models of holiness, e.g., St. Francis of Assisi, St. Teresa of Avila, St. Ignatius of Loyola, St. Thomas More, St. Francis de Sales, St. John Vianney, St. Therese of Lisieux, and Mother Teresa. In any event, the practice of mortification as lived in Opus Dei gives more emphasis to everyday sacrifices than to these greater sacrifices, and is not like the distorted and exaggerated depiction in The Da Vinci Code.
Pope John Paul II: “What one must see in these forms of penance – which, unfortunately, our times are not accustomed to – are the motives: the love of God and the conversion of sinners.” Letter to Priests on Holy Thursday, no. 11, March 16, 1986.
New Catholic Encyclopedia (2003): “Mortification. The deliberate restraint that one places on natural impulses in order to make them increasingly subject to sanctification through obedience to reason illumined by faith. Jesus Christ required such renunciation of anyone who wished to come after Him (Lk 9.29). And so mortification, or what St. Paul calls the crucifixion of the flesh with its vices and concupiscences (Gal. 5.24), has become a distinguishing mark of those who are Christ’s.
“All theologians agree that mortification is necessary for salvation because man is so strongly inclined to evil by the threefold concupiscence of the world, the flesh, and the devil, which, if not resisted, must lead to grievous sin. One who wishes to save his soul must, at the very least, flee the proximate occasions of mortal sin. Of itself, such flight involves some mortification. In addition to these mortifications demanded by man’s very condition, the Church, in view of the repeated insistence of the Gospels, imposes other restraints on the faithful. One example is the law of fast and abstinence. And those who, for one reason or other, are dispensed from such regulations, are advised of their duty to perform some mortification in their place.
“Those who seek to advance in Christian perfection must mortify themselves more than ordinary believers are required to do. Christ made the bearing of a cross the price of being His close follower (Lk 14.33). Hence, from early Christian times, many embraced a life of mortification in imitation of the Lord. Those who achieve great sanctity are constantly moved to be like Him in His suffering. But because of the danger of self-deceit in assuming great mortifications, they are advised to submit all penances to the approval of a wise director.”
The Bible (RSV): “If any man would come after me, let him deny himself and take up his cross daily and follow me” (Jesus, Luke 9:23). “Now I rejoice in my sufferings for your sake, and in my flesh I complete what is lacking in Christ’s afflictions for the sake of his body, that is, the church” (St. Paul, Col. 1:24).
Catechism of the Catholic Church (1997): “By uniting ourselves with his [Christ’s] sacrifice we can make our lives a sacrifice to God” (n. 2100). “The way of perfection passes by way of the Cross. There is no holiness without renunciation and spiritual battle. Spiritual progress entails the ascesis and mortification that gradually lead to living in the peace and joy of the Beatitudes” (n. 2015).
Pope Paul VI: “True penitence, however, cannot ever prescind from physical ascetism as well…. The necessity of mortification of the flesh stands clearly revealed if we consider the fragility of our nature, in which, since Adam’s sin, flesh and spirit have contrasting desires. This exercise of bodily mortification—far removed from any form of stoicism—does not imply a condemnation of the flesh which the Son of God deigned to assume. On the contrary, mortification aims at the ‘liberation’ of man.” Apostolic Constitution Paenitemini, February 17, 1966.
Blessed Pope John XXIII: “No individual Christian can grow in perfection, nor can Christianity gain in vigor, except it be on the basis of penance. That is why in Our Apostolic Constitution officially proclaiming the Second Vatican Council and urging the faithful to make a worthy spiritual preparation for this great event by prayer and other acts of Christian virtue, we included a warning to them not to overlook the practice of voluntary mortification.” Encyclical Paenitentiam Agere (On the Need for the Practice of Interior and Exterior Penance), July 1, 1962.
Jordan Aumann, O.P.: “One of the most tremendous marvels of the economy of divine grace is the intimate solidarity of all people through the Mystical Body of Christ. God accepts the suffering offered to him by a soul in grace for the salvation of another soul or for sinners in general. It is impossible to measure the redemptive power of suffering offered to divine justice with a living faith and an ardent love through the wounds of Christ. When everything else fails, there is still recourse to suffering to obtain the salvation of a sinful soul. The Curé of Ars [St. John Vianney] said once to a priest who lamented the coldness of his parishioners and the sterility of his zeal: ‘Have you preached? Have you prayed? Have you fasted? Have you taken the discipline? Have you slept on boards? Until you have done these things, you have no right to complain.’” Spiritual Theology (London: Sheed and Ward, 1993), p. 172.
For an assessment of the portrayal of mortification in The Da Vinci Code see the comments of Bishop Robert Morlino (Madison, WI) in the Catholic Herald.