During the prayers of the Mass we hear the priest say;
You are indeed Holy, O Lord, the fount of all holiness.
Make holy, therefore, these gifts, we pray, by sending down your Spirit upon them like the dewfall, so that they may become for us the Body and Blood of our Lord Jesus Christ (Eucharistic Prayer II).
In the Dogmatic Constitution on the Church the council fathers define the Church as the “the universal sacrament of salvation” through which the faithful are joined to Christ and are nourished with His own Body and Blood (LG 48). By being joined to Christ through Baptism, Confirmation and reception of the Holy Eucharist and we become one with Christ.
St. Augustine comments on the deeper significance of our oneness or communion with Christ in his commentary on Psalm 26. He notes that the practice of anointing in the Old Testament was normally reserved for either the king or the priest. But Christ now holds both offices as both Priest and King in virtue of his anointing or literally being the Messiah or Anointed one. Speaking of Christ, St. Augustine observes, “But not only was our Head anointed; but his body was too, we ourselves. . . . From this it is obvious that we are the body of Christ, being all anointed. In him all of us belong to Christ, but we are Christ too, because in some sense the whole Christ is Head and body” (Exposition 2 of Psalm 26).
We not only become like Christ in Baptism but we actually become a New Creation which is joined to the New Adam—Christ Jesus. This is not a mere exterior conformity but an interior transformation which results in us in a sense becoming Christ himself.
St. Augustine notes that, “all who have been anointed by his chrism we can rightly call christs and yet there is one Christ: the whole body with its Head” (City of God XVII, 4). As the Catechism reminds us; “The ministerial or hierarchical priesthood of bishops and priests, and the common priesthood of all the faithful participate, "each in its own proper way, in the one priesthood of Christ" (CCC 1547).
Our participation in the Holy Eucharist makes us partakers of the “fount of all holiness” and in the person of the ‘Holy One of God’ (John 6:69). Christ shares his priestly soul with us. The council Fathers emphasize this even of the laity, “The supreme and eternal Priest, Christ Jesus, since he wills to continue his witness and service also through the laity, vivifies them in this Spirit and increasingly urges them on to every good and perfect work” (LG 34).
As a result of this the council fathers inserted an entire chapter on the ‘Universal Call to Holiness.’ (LG 39-42). By virtue of our Baptism, every single Christian, regardless of their state of life, is called to be holy. As the council fathers note; “Therefore in the Church, everyone whether belonging to the hierarchy, or being cared for by it, is called to holiness, according to the saying of the Apostle: ‘For this is the will of God, your sanctification’ (1 Thessalonians 4:3; cf. Ephesians 1:4)” ( LG 39). Although there are many different gifts and vocations in the Church, no one can escape the call to holiness. We might be tempted to differentiate priests and religious from laity and to think that the laity are just ordinary folk who have no special calling. We do not want to down play the unique call to holiness of bishops, priests and deacons, or of those who live as religious. Yet these callings do not let ordinary Catholics off the hook. There are no exclusions from the call to holiness. As the fathers note, “The classes and duties of life are many, but holiness is one—that sanctity which is cultivated by all who are moved by the Spirit of God, and who obey the voice of the Father and worship God the Father in spirit and in truth” (LG 41).
Perhaps the most misunderstood of notion of holiness is its application to the lay faithful. In the Decree of the Apostolate of the Laity, the council fathers note;
In the Church there is a diversity of ministry but a oneness of mission. Christ conferred on the Apostles and their successors the duty of teaching, sanctifying, and ruling in His name and power. But the laity likewise share in the priestly, prophetic, and royal office of Christ and therefore have their own share in the mission of the whole people of God in the Church and in the world.
They exercise the apostolate in fact by their activity directed to the evangelization and sanctification of men and to the penetrating and perfecting of the temporal order through the spirit of the Gospel. In this way, their temporal activity openly bears witness to Christ and promotes the salvation of men (AA 2).
The lay faithful are to be like leaven in the midst of the world. Our daily work then can be a means of our personal sanctification; a means of sanctifying others and a means of bringing about the sanctification of the whole world. One modern Saint who has emphasized these ideas is St. Josemaría Escrivá, the founder of Opus Dei.
At his canonization, Pope John Paul II called him the Saint of Ordinary Life. Saint Josemaría repeatedly emphasized: “you have to sanctify your work, be sanctified in your work, and sanctify through your work.” He noted that work is “the hinge on which our calling to holiness is fixed and turns” (Friends of God, n. 62). For the lay faithful, holiness begins in the daily grind of our ordinary life.