Gender is a topic of much concern in the Catholic Church, which reserves the sacrament of Holy Orders to men. This means that women cannot be deacons, priests, or bishops and effectively excludes them from all higher levels of Church service and authority where ordination is a prerequisite. It is the Church's longstanding belief that women should not be admitted to the priesthood because Christ did not choose any women to be among his closest twelve disciples, whom Catholics view as the first Christian ministers. If Christ chose only men despite his willingness to break many social norms where women are concerned, then it is because he wished to institute the ministerial role for men alone.
The question of women in the priesthood remains very much alive despite Pope John Paul II's forceful statements in the Apostolic Letter Ordinatio Sacerdotalis (1994), declaring 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." Some modern Catholics argue that Christ's choice reflected a particular societal context and that the exclusion of women from the priesthood and the diaconate is now a matter of politics and power. They believe the Church should recognize that women's creation in the image of God enables them to stand in service to others just as fully as men, and that the thinking that has kept this from happening is not immortal truth but a changing social definition. Traditionally the Church taught that women were not created with the same degree of perfection as men, unable to reason as well or reflect God as fully. While this conception of women, explicitly laid out by St. Thomas Aquinas, is no longer taught, many modern Catholics believe that the Church's current teachings remain subtly informed by it.
Women's exclusion from the priesthood was long a barrier to the diaconate as well, since deacons were merely priests in training. With Vatican II's restoration of a diaconate that does not lead to the priesthood, women's ability to fulfill this role has become more of an open question. In fact, Pope Paul VI commissioned a study to determine whether women could serve in the diaconate, but it was never published and the whole issue has been effectively tabled. The Church has not definitively stated that women will never be restored to the diaconate, a role that was open to them in New Testament times and for many centuries thereafter, but such a restoration does not appear to be on the immediate horizon.
Beyond the realm of ordination, though, the modern Church strongly affirms the dignity and worth of women. The same Pope John Paul II who definitively excluded women from the priesthood had written a few years earlier in Mulieris Dignitatem (1988) of women's vital role in the Church, their importance in the family and in society, their equal worth before God, and the need to break down societal barriers such as unequal pay that have kept them in secondary status. He repeatedly taught that the highest role any human has ever been granted by God belonged to the Blessed Virgin Mary, whom he referred to as Co-Redemptrix with her Son. In fact, in the apostolic letter barring women from the priesthood John Paul points out that this cannot indicate a lack of dignity or worth in women because Mary herself was not included among Christ's closest disciples.
Despite their exclusion from the priesthood and the diaconate, women are allowed to serve the Church in many capacities. They are the backbone of the Church, performing some 85% of all parish work. Women take on roles of particular holiness as nuns who commit their lives to Christ through service in the Church, and there are now women serving on many Vatican commissions and councils, although their numbers are not large.
The Church's teaching on sexuality moves along conservative lines. The Church recognizes that all people are sexual beings, and Catholics believe that sexuality is a great and wonderful gift that allows humans to become co-creators of life with God. They also believe that this gift must be used properly, which means that the full genital expression of sexuality is reserved for those who have already sacramentally vowed themselves in selfless love to each other in marriage. It is the very sacredness of the sexual union that leads to this belief: such a sacred joining should not be made in a casual context, or one where the participants do not recognize the sacrality of their actions. All forms of genital sexual contact outside of marriage are forbidden, including adultery and pre-marital sex. Catholic teaching holds that marriage must take place between a man and a woman, meaning that all homosexual activity is considered disordered whether the state recognizes same-sex unions or not. Catholics believe that it is homosexual actions, rather than the fact of being homosexual, that is sinful, that God calls those who have homosexual desires to lives of celibacy and restraint.