1. As question C explained, doing penance—that is, making reparation for sin—is an essential part of the sacrament of penance. One who has injured another by unfaithfulness and then been reconciled can best make up for the offense by whatever self-denial is needed to assure, so far as possible, that the offense will not be repeated. Thus, a determined effort to deal with occasions of sin is an especially suitable expression of penitential love of God.
2. Not only the self-denial involved in avoiding occasions of sin, but all forms of self-denial can serve as reparation. Since self-denial is required throughout Christian life, its penitential significance is another way in which the sacrament of penance can be a principle of the whole of Christian life. (The explanation of this point will help to clarify the significance of the prayer quoted at the end of question C above.)21
Christian self-denial does not mean despising or rejecting created goods insofar as they are goods. It flows from the insight that all human activity is infected by sin, that progress means the healing of this infection, and that healing sometimes requires radical surgery and involves unpleasant medicine: “Hence if anyone wants to know how this unhappy situation can be overcome, Christians will tell him that all human activity, constantly imperiled by man’s pride and deranged self-love, must be purified and perfected by the power of Christ’s cross and resurrection. For, redeemed by Christ and made a new creature in the Holy Spirit, man is able to love the things themselves created by God, and ought to do so” (GS 37). Thus all of one’s life must be purged of the effects of sin.
3. “Self-denial” has various meanings. It can refer to detachment, moral practice, mortification, and resignation.
4. Detachment is the surrender of any interest, desire, or objective which would keep one from using all one’s time, energy, and resources to love God and neighbor. It is self-liberation for service. To do everything for God’s glory and in Jesus’ name (see 1 Cor 10.31; Col 3.17) it is necessary to set aside any relationship, possession, or power which interferes with total dedication. Detachment was treated previously as one of the basic modes of Christian response (26‑F).
5. Moral practice, asceticism in the strict sense, is a matter of doing good works which one would not choose for their own sake but which are done for practice or training, so that one can do other, more difficult good works when the responsibilities of Christian life require them. The metaphors of pursuing a prize in a race and of training for war (see 1 Cor 9.24–27; Eph 6.10–17; Phil 1.27; 3.8–16; 1 Tm 4.7–10) suggest the model of asceticism in its narrow sense: arduous practice which trains one to resist temptations to sins of sensory gratification.
6. Mortification is the putting to death of sin so that one can fully live for goodness in Christ (see Rom 6.6–23; Gal 5.24). Physical practices are appropriate for this purpose, but so are spiritual forms of mortification. When one speaks of mortification, what is usually in question is an especially determined and systematic campaign against sin, not only mortal sin but venial sin. From a positive viewpoint, mortification is vivification; it is the use of every ability and part of oneself to contribute to fulfillment in Christ (see DS 1535/803). Mortification pertains to Christian devotion, treated previously (26‑I).
7. Resignation is acceptance, out of love of God, of the evil that befalls one, insofar as every such occurrence must have been permitted by God, directed to some good by his wise and loving providence, and intended as a challenge to one’s ingenuity or patience. When Christian, transforming love cannot at once heal an evil, it is the work of resignation simply to endure it patiently. This is especially necessary in regard to incurable suffering and death. Resignation is an aspect of Christian dedication and meekness, treated previously (26‑E). As will be explained below, it is especially related to the sacrament of anointing of the sick.
8. Although the various aspects of Christian self-denial can be distinguished in this way, they are in fact closely related. The Christian’s sharing in the cross of Jesus embraces all of them: “If any man would come after me, let him deny himself and take up his cross and follow me” (Mk 8.34; cf. Mt 16.24–28; Lk 9. 23–27).
9. Like Jesus, each Christian must live a life detached from many good things which would interfere with holiness and witness, must engage in moral practice, must accept suffering, death, and other evils with submission to God’s will. Even if a person never committed a personal sin, self-denial in these forms would be necessary in Christian life. Like Jesus and Mary, one still could offer penance for the sins of others (see S.t., sup., q. 13, a. 2). And, to become more like Jesus, we sinners must practice mortification.
10. All the various forms of self-denial are components of the work of penance for us who have an obligation to make up for our own sins. Detachment, asceticism, mortification, and resignation undo the moral effects of one’s sins by reversing the subordination of love to self-assertion and submitting one’s whole self to the requirements of love.
The situation can be clarified by the analogy of the adulterous husband. Even a faithful husband must give up some personal satisfactions for the sake of marriage, avoid the occasions of adultery, accept his wife’s limitations, and so on. But an unfaithful, repentant, and reconciled husband must do all these things more generously and more thoroughly, if the marital relationship is to be restored to its full confidence and affection. Similarly, the repentant Christian must practice all the forms of self-denial and self-giving appropriate in Christian life, but now as forms of penance.
11. Because no good act of the Christian can be done without self-denial of some kind and to some degree, and because every act of self-denial becomes part of reparation for the penitent Christian, every good act of Christian life is ordered to a penitential life. Insofar as doing penance is part of the sacrament of penance, the sacrament effects this ordering for those who receive forgiveness in it.
The suffering of tribulations as a condition for the coming of the kingdom was proclaimed in the Old Testament, for example, in Daniel. Thus Christians were not surprised by their sufferings (see Lk 24.26; Acts 14.22; 17.3; 1 Thes 1.6; 2.14–15; 3.2–3; 2 Thes 1.3–5; and so on). Suffering with Jesus is a condition of being glorified with him (see Rom 8.17–18; Phil 3.10–11). The apostolic life, to which every Christian is called (31‑B), cannot be without suffering (see 2 Cor 4.7–12; Eph 3.1–19; Phil 3.17–19; Col 1.24–29).
The imitation of Jesus is an imitation of his self-denial. It also is an imitation of his endurance unto glory (see Heb 12.1–4). Vatican II teaches that we are made like Christ by baptism. “Still in pilgrimage upon the earth, we trace in trial and under oppression the paths he trod. Made one with his sufferings as the body is one with the head, we endure with him, that with him we may be glorified (cf. Rom 8.17)” (LG 7). The whole of Christian life is a putting on of the new man, created in God’s image, and a putting off of the old self, with its illusions and false desires (see Eph 4.17–24).
To share in the divine nature with Jesus is to separate oneself from the corrupt world (see 2 Pt 1.3–11). Faithfulness to our Lord Jesus necessarily means division from others who do not accept him (see Mt 10.34–36; Lk 12.51–53). To sanctify themselves by suffering and to redeem the world, the followers of Jesus are left in the world, to which they do not belong (see Jn 17.15–16). Consecrated to the truth, Christians have God’s Word to communicate; for this the unbelieving world inevitably hates them (see Jn 17.14).
Since Jesus’ self-denial was entirely for others, we are likely to overlook the extent to which our struggle against our own sin and its consequences within us is a sharing in the passion of Jesus. Yet it is clear that there is an important aspect of Jesus-likeness in this struggle. So there is a great nobility in it which we tend to overlook. Perhaps we forget that as Christians and sinners we are split personalities: victims of our own freedom as sinners, but beneficiaries of God’s grace as Christians united with Jesus in a redemptive work which we must carry out—first of all in ourselves.
There is a natural tendency to wish to avoid and forget about this painful, negative aspect of Christianity. One thinks one perhaps ought to be exempted from suffering. But although Jesus loved his mother dearly, he did not prevent her suffering along with himself, as Vatican II teaches: “. . . the Blessed Virgin advanced in her pilgrimage of faith, and loyally persevered in her union with her Son unto the cross. There she stood, in keeping with the divine plan (cf. Jn 19.25), suffering grievously with her only-begotten Son. There she united herself with a maternal heart to his sacrifice, and lovingly consented to the immolation of this Victim which she herself had brought forth” (LG 58).
Surely, the great sorrow any mother naturally feels at the death of her child was increased immeasurably in Mary’s case by the following facts: Jesus was her only child; Joseph almost certainly already had died; the relationship between Jesus and Mary was unmarred by selfishness on either side; the killing of Jesus was unjust; the manner of his death was unusually cruel; Mary was present but unable to do anything tangible to help. God did not permit Mary to suffer so much except for the great good of the closeness to Jesus she achieved in this gift of suffering. This good and gift, like everything in Mary, are proposed to us as a model for our own lives.
21. See Leeming, op. cit., 364–65, on the significance of this prayer and its relationship to absolution and to the permanence of the sacrament in the life of the person who receives it.