Members try to incorporate an element of sacrifice into their lives. Although traditional Catholic practices of penance and mortification are not discouraged, Opus Dei places more emphasis on the sacrifices involved in daily life: carrying out one’s duties conscientiously, putting others’ needs before one’s own, finding a smile in annoying circumstances, and so on.

In addition, as recommended by the Catholic Church, all members practise small corporal mortifications such as fasting in moderation, going without certain items of food or drink occasionally, etc. Within this spirit, numeraries and associates practise certain traditional forms of corporal mortification such as using the cilice, a discipline or sleeping on a hard surface. These are traditional practices that Catholics have used for centuries and are commonplace in the lives of the saints, for example: St Francis of Assisi, St Thomas More, St Therese of Lisieux, Pope Paul VI, St Padre Pio and Mother Teresa of Calcutta. The motivation behind these voluntary mortifications is to imitate Christ and to join him in his redemptive sacrifice (cf. Matthew 16:24), and they can also be a way to suffer in solidarity with the many poor and deprived people in the world.