For example, he did not hesitate to speak with the Samaritan woman even though custom forbade it (cf. Jn 4:4-42). But it was only men whom he chose to be the Twelve Apostles and the foundation of the ministerial priesthood.
Although after the Ascension, Mary occupied a privileged place in the little circle gathered in the Upper Room, she was not called to enter the college of the Twelve at the time of the election of Matthias. The Apostles continued Christ’s practice and so, too, did their successors through the centuries.
The Church has the power to determine the way in which the Sacraments are to be celebrated, but she has no ability to change the essential aspects established by the Lord Jesus. Sacramental signs are natural, but they also carry a divine meaning. Just as the Eucharist is not only a communal meal, but also makes present the saving sacrifice of the Lord Jesus, so too ministerial priesthood is more than pastoral service: it ensures the continuity of the ministry Christ entrusted to the Apostles.
The priesthood has a sacramental nature. The priest is a sign of what is happening. Sacramental signs represent what they signify by a natural resemblance. This resemblance is as true for persons as for things. When the priest acts in the person of Christ, he takes on the role of Christ, to the point of being his representative. He is a sign of what is happening and must be a sign that is recognizable, which the faithful can see with ease.
An image used to explain this reality talks of a priest as an “icon” of Christ. An icon is a religious painting that is considered to make present the mystery of salvation or the saint it depicts. To say a priest is an icon of Christ means, then, that a priest is not just a reminder or image of Christ but is also a real means by which a person can be touched by Christ. Because Christ is a man, it is fitting that a priest as the icon of Christ should also be a man.
Another reason why the Church understands that ordination is reserved to men is the recognition of the priest’s responsibility to reflect Christ as the Bridegroom of the Church. This image and understanding can be reflected most truly only when the priest is a man.
The teaching that priestly ordination is to be reserved to men alone has been preserved by the constant and universal Tradition of the Church (cf. Sacred Congregation for the Doctrine of the Faith, Declaration on the Admission of Women to the Ministerial Priesthood [ Inter Insigniores ], nos. 9‑10, 13, 20‑21, 26‑27). Pope John Paul II reaffirmed this teach- ing in these words: “In order that all doubt may be removed, I declare that the Church has no authority whatsoever to confer priestly ordination on women and that this judgment is to be definitively held by all the Church’s faithful” ( On Reserving Priestly Ordination to Men Alone [ Ordinatio Sacerdotalis ], no. 4). In that same document, the Pope underlined the incomparable achievements of women for the benefit of the People of God:
The New Testament and the whole history of the Church give ample evidence of the presence in the Church of women, true disciples, witnesses to Christ in the family and in society, as well as in total consecration to the service of God and of the Gospel. “By defending the dignity of women and their vocation, the Church has shown honor and gratitude for those women who, faithful to the Gospel, have shared in every age in the apostolic mission of the whole People of God. They are the holy martyrs, virgins and mothers of families, who bravely bore witness to their faith and passed on the Church’s faith and tradition by bringing up their children in the spirit of the Gospel.”
Ordination to the priesthood is always a call and a gift from God. Christ reminded his Apostles that they needed to ask the Lord of the harvest to send laborers into the harvest. Those who seek priesthood respond generously to God’s call using the words of the prophet, “Here I am, send me” (Is 6:8). This call from God can be recognized and understood from the daily signs that disclose his will to those in charge of discerning the vocation of the candidate.
When God chooses men to share in the ordained priesthood of Christ, he moves and helps them by his grace. At the same time, he entrusts the bishop with the task of calling suitable and approved candidates and of consecrating them by a special seal of the Holy Spirit to the ministry of God and of the Church ( Admission to Candidacy for Priesthood, 5).
All candidates for ordination in the Latin Church—with the exception of permanent deacons, who can be married at the time of their ordination—are chosen from among those who intend to remain celibate “for the sake of the kingdom of heaven” (Mt 19:12). Their celibacy is a sign of their intention to imitate Christ’s own celibacy and to serve God in the Church’s ministry with an undivided heart. In some cases, married clergy of other Christian churches who convert to Catholicism have been admitted to Holy Orders. In the Eastern Churches, only the bishops must be celibate. Priests and deacons may be married; however, in the United States, priests in Eastern Churches are normally celibate.