Society is like a fabric woven of human relationships. Work, family and other daily circumstances create a web of human bonds whereby our life becomes “interwoven" with the lives of many other people. So when we strive to sanctify our specific profession, our particular family situation, and our other daily duties, we are not sanctifying simply an isolated thread, but the whole social fabric.
This sanctifying effectiveness makes Christians a powerful leaven for restoring order to the world, so that it may better reflect the love with which it was created. When charity is present in any human activity, there is a less room for selfishness, the principal factor of disorder in the human heart and in our relationships with one another and with God's creation. Thus, bearers of the Love of the Father in the midst of society, the lay faithful “are called there by God that by exercising their proper function and led by the spirit of the Gospel they may work for the sanctification of the world from within as a leaven."
The transforming strength of this Christian leaven in work depends, to a great extent, on each one's trying to achieve an adequate preparation. This effort should not be restricted to the specific knowledge, whether technical or intellectual, required by any job or profession. Other aspects that are indispensable for attaining a true human and Christian “competence" have a very direct influence on workplace and social relations, making of our work a true sowing of Christian charity: the way we listen, understand, get on with the others, forgive and ask for forgiveness, and smile.
Being in the world without being worldly
Christians called to seek sanctity in their work need to be in the world, but without being worldly. They seek to be successful in life, but don't consider it as the supreme good. They are realistic in recognizing the presence of evil in the world but aren't discouraged when they meet it. Rather they try to set it right and struggle with greater effort to purify the world of sin. “You should never lack enthusiasm, either in your work or in your effort to build the temporal city. But at the same time, as disciples of Christ who have crucified the flesh with its passions and desires (Gal 5:24), you strive to keep alive the sense of sin and of generous reparation, in the face of the false optimism of those who, enemies of the cross of Christ (Phil 3:18), see everything in terms of progress and human effort."
Being in the world, in a positive sense, leads us “to have a contemplative spirit in the midst of all human activities . . . making this aim a reality: the more within the world we are, the more we must be God's." This aspiration, far from holding us back in the face of difficulties in our surroundings, spurs us to a greater daring, the fruit of a more intense and constant presence of God. Because we are in the world and also in God, we cannot shut ourselves off from the world around us: “it is not licit for Christians to abandon their mission in the world, just as the soul cannot separate itself voluntarily from the body." Saint Josemaria specifies the task of Christian citizens when he tells us: “Your task as a Christian is to help see Christ's love and freedom preside over all aspects of modern life: culture and the economy, work and rest, family life and social relations."
An important manifestation of Christian spirit, and also of a truly human one, is to recognize that full human happiness is found only in union with God, not in the possession of earthly goods. It is, indeed, exactly the contrary of being worldly. The worldly person puts his whole heart into the goods of this world, without considering that they are meant to lead us towards the Creator. It may sometimes happen, on seeing people distant from God who seem to find happiness from possessing the material goods they desire, that the thought may come that union with God is not the only source of complete joy. But we should not be deceived. Theirs is an unstable happiness, one that is superficial and never free of anxiety. Those very people would be incomparably more happy, both in this world and afterwards fully in heaven, if they were close to God and ordered the use of these goods to his glory. Their happiness would cease being fragile, exposed to all of life's circumstances, and they would lose their fear—a fear that robs them of peace—that they might fail to hold on to their material possessions. Nor would the reality of suffering and death frighten them.
The Beatitudes in the Sermon on the Mount teach us that the fullness of happiness, of true beatitude, is never found in the goods of this world: Blessed are the poor in spirit, for theirs is the kingdom of heaven. Blessed are those who mourn, for they shall be comforted. Blessed are the meek . . . those who hunger and thirst for righteousness . . . those who are persecuted for righteousness' sake.... It hurt Saint Josemaría to see that often souls are deceived: "One hears talk of a liberation that is not Christ's. The teachings of Jesus, his Sermon on the Mount, those beatitudes that are a poem of divine love, are all ignored. The only thing sought is an earthly happiness, which it is not possible to attain in this world."
Nevertheless, our Lord's words do not justify a negative outlook on worldly goods, as though they were evil or an impediment to reaching heaven. They are not an obstacle, but rather the material we are called to sanctify. Jesus didn't ask us to reject them. He said that only one thing is needful for sanctity and happiness: to love God. Whoever lacks these goods or who suffers should realize not only that the fullness of joy is found only in heaven, but that also in this life they are “blessed." They can enjoy here a foretaste of the happiness of heaven, because suffering, and in general, the lack of a material good, has redemptive value if it is accepted out of love for the Will of our Father God, who orders everything to our good.
To seek material well-being for those around us is very pleasing to God. It is a marvelous way to imbue temporal realities with charity, and is perfectly compatible with the personal attitude of detachment that our Lord has taught us. An example of this can be found in the home: As Saint Josemaria said: “The mother of a family has to try to ensure that in her home there is a minimum of well-being, a well-being in proportion to the family's situation, but without forgetting about the needy. So that among the expenses in your home, you should set aside a certain percentage, which depends upon your generosity and that of your husband, to assist those who have nothing. Do you agree?
“When you are concerned about the material well-being of your husband, of your children, or your own, you are not offending God. For you have the duty intrinsic to the state of matrimony to try to ensure that your family finds life at home pleasant. The mother of a family who was not concerned about material things in the home and the well-being of her family, would not be pleasing Jesus."
Lay mentality, with a priestly soul
A child of God must have a “priestly soul," because he or she has been made a sharer in Christ's priesthood in order to co-redeem with him. For the faithful of Opus Dei, who are called to seek sanctity in the middle of the world, this characteristic is found intrinsically united to a “lay mentality," which leads to carrying out one's work and daily duties competently, in accord with their intrinsic laws, willed by God.
Within the basic framework of the norms of professional morality (which need to be observed with great care as a necessary prerequisite for sanctifying one's work), there are many ways of carrying out human tasks in accord with God's will. Within the laws intrinsic to each activity, and in the broad perspective that Christian morality opens up, many different options exist, all of which can be sanctified. Each person is free to choose among these option with personal responsibility, while respecting the freedom of others. This inalienable freedom makes each person's participation in social life—in the home, at work, in living alongside others—unique and unrepeatable, just as each soul's response to God's love is unrepeatable. We must not deprive the human family of the right exercise of our freedom, source of initiatives in the service of others for God's glory. The Founder taught us that this characteristic is essential to the spirit of Opus Dei. “Freedom, my children, freedom, which is the key to the lay mentality that we all have in Opus Dei."
Priestly soul and lay mentality are two inseparable aspects on the path to sanctity taught by Saint Josemaria. “We must have always and in everything—both priests and laity—a truly priestly soul and a fully lay mentality, so that we can understand and exercise in our personal life the freedom we enjoy in the sphere of the Church and in temporal realities, seeing ourselves at the same time as citizens of the city of God (cf. Eph 2:19) and of the city of men."
We need this union in our own life in order to be a leaven of Christian spirit in society, so that all our professional work, carried out with a lay mentality, is permeated with a priestly soul.
A clear sign of this union is putting our dialogue with God, piety, in first place, specified in carrying out a daily plan of spiritual life. We need to nourish Love as the vital impulse in our life, since it is impossible to truly work for God without constantly deepening our interior life. Saint Josemaria insisted: “If you did not have interior life, when you applied yourself to your work, instead of divinizing it, there could happen to you what happens to iron, when it glows red hot and is plunged into cold water: it loses its heat and goes cold. You need to have a fire that comes from within, that does not go out, that enkindles all it touches. That's why I have said that I don't want any work, any undertaking, if my children don't improve in it. I measure the effectiveness and value of work by the degree of sanctity acquired by the instruments who carry it out.
“With the same insistence with which I previously invited you to work, and work well, without fear of growing tired, I now invite you to have interior life. I will never tire of repeating it: our Norms of piety, our prayer, come first. Without ascetical struggle our life would be worth nothing; we would be ineffective, sheep without a shepherd, blind leading the blind (cf. Mt 9:36; 15:4)."
For the leaven not to lose its effectiveness, it needs God's strength. God is the one who transforms. Only when we stay united to him are we truly a leaven of sanctity. Otherwise we will be present in the mass of society without contributing anything expected of leaven. The effort to care for a daily plan of spiritual life will end up producing the miracle of God's transforming action: first in ourselves, since this plan is a path to union with him, and then, as a consequence, in others, in the whole of society.
 Cf. Vatican Council II, Dogm. Const. Lumen gentium, no. 31, and John Paul II, Apost. Ex., Christifideles laici, December 30, 1988, no. 15.
 Saint Josemaria, Letter, January 1, 1959, no. 19.
 Saint Josemaria, The Forge, no. 740.
 Epistola ad Diognetum, 6.
 Saint Josemaria, Furrow, no. 302.
 Mt 5:3ff.
 Saint Josemaria, Notes taken in a meditation, December 25, 1972.
 Lk. 10:42
 Cf. Rom 8:28.
 Saint Josemaria, Notes taken in a get-together,
 Saint Josemaria, Letter, September 29, 1957, no. 55.
 Saint Josemaria, Letter, February 2, 1945, no. 1.
 Saint Josemaria, Letter, October 15, 1945, nos. 20-21.