Human beings are sexual beings. Since our bodies are part of who we are and a vital dimension of the way we exist in, and interact with, the world, our biological makeup as members of a species that procreates through sexual reproduction is of significance when thinking about what it means to be human and how we should best be human. Each human being exists as a specific kind of sexual being. Usually this is as either a male or a female. In the Genesis narratives, we read about how God created human beings, male and female, in God's image. In other words, being male and being female are two ways of being a human body (John Paul II, General Audience, 7 November 1979). Sex education should also include respect and appreciation for differences, as a way of helping the young to overcome their self-absorption and to be open and accepting of others (Pope Francis, 2016 Amoris Laetitia).

Human beings are created for unity. Put bluntly, male genital organs and female genital organs are both necessary for reproduction and no human can procreate alone in any natural way. But this complementarity extends beyond simple physical necessity and compatibility. Rather, as Pope St John Paul II (General Audience, 7 November 1979) has argued in his interpretation of the second Genesis narrative, men and women are better together. In Genesis, God decides that it is not good for the first human being (who arguably has no sexual identity) to be alone. Despite the presence of all the animals the first human being is not happy. So God puts the human being to sleep and creates another human being from the same flesh (the rib) of the first human being. When they awaken, the first human being recognizes the second as 'flesh of my flesh' and expresses, for the first time, joy. In other words, human beings find joy and completion in other human beings. Man and woman find joy and completion in each other. The complementarity of woman and man is characterised by: a) equal dignity; b) significant difference; c) synergetic relation—meaning something more happens when you have woman and man together, e.g. generation of a child or generation of the joy of mutual love; d) intergenerational fruition—in other words the human species and the expression of culture goes on generation after generation after generation across historical time. (Allen, 2014).

Men and Women are fundamentally equal. Man and woman are both human beings. Theologically speaking the creation of human beings precedes the creation of the sexes. Women and men are of equal worth or dignity in the eyes of God. Both male and female are made in God's image and both are called to share in the future God promises. Yet, this fundamental equality does not mean that being a man and being a woman is the same thing. Rather it is equally good to be man as it is to be a woman and neither sex should think of itself as superior in some fundamental or essential way to the other. Man and woman share the same humanity. They are both made in God's image sharing a basic mutuality. Both are called to live in a covenant of love (United States Conference of Catholic Bishops, 1991). Consequently, sexism, that is, the unjust discrimination to the detriment of a person on the basis of his or her sex is not to be tolerated. Since all human beings, whether male or female, share the same dignity or moral worth each gender has an equal claim to the natural human rights that proceed from this worth. Similarly, each gender has a duty to work for the common good and to respect the dignity and rights of others. True, all human beings are not alike from the point of view of varying physical power and the diversity of intellectual and moral resources. Nevertheless, with respect to the fundamental rights of the person, every type of discrimination, whether social or cultural, whether based on sex, race, color, social condition, language or religion, is to be overcome and eradicated as contrary to God's intent (Vatican Council II, Gaudium et Spes, para. 29).

Sexuality refers to a fundamental component of personality in and through which we, as sexual beings, experience our relatedness to self, others, the world and God. Sexuality involves the whole person. Education in sexuality is not to be limited to talking about sexual intercourse, to sexual attraction, or to 'the flesh'. Sexuality is a powerful force for emotional and spiritual union housed in the physical body. A wholistic understanding of human sexuality flows from the idea that human beings are created in the image of God, the Imago Dei, as unique individuals who are loved and called by God. Living wholeheartedly looks to the integration of the multiple dimensions of the human person, including one's sexuality, in a way that contributes to one's own flourishing and the flourishing of the community. There is a sense in which sexuality is identifiable with the principle of life itself. Here, sexuality is associated with our drive for love, communion, community, friendship, family, affection, wholeness, consummation, creativity, self-perpetuation, immortality, joy, delight, humour, and self-transcendence. It is about overcoming separateness by giving life and blessing it (Rolheiser, 1999 pp. 195, 198). Sexuality, when fully embraced as a gift, touches all aspects of the human person and manifests its deepest meaning in leading the person to the gift of self in love (John Paul II, 1981).

Sexuality must be grounded in respect for the power of sexuality to either enrich or diminish life. While sexuality is good and central to the unity of body, mind and spirit, sexuality can also be distorted and misused. The human sexual condition includes sexual abuse, sexual torture and sexual exploitation of the vulnerable by the strong (Callahan, 2007 p. 79). The results of fractured sexual relationships are often experienced as terrible heartaches, family breakups, and violence (Rolheiser, 1994 p. 199). Sexuality in the context and conviction of the Christian vision is situated within loving and just relationships and the enhancement of the human vocation. On the basis of a positive vision of sexuality, we can approach the entire subject with a healthy realism. It is, after all, a fact that sex often becomes depersonalised and unhealthy; as a result, 'it becomes the occasion and instrument for self-assertion and the selfish satisfaction of personal desires and instincts'. In our own day, sexuality risks being poisoned by the mentality of 'use and discard'. The body of the other is often viewed as an object to be used as long as it offers satisfaction, and rejected once it is no longer appealing. Can we really ignore or overlook the continuing forms of domination, arrogance, abuse, sexual perversion and violence that are the product of a warped understanding of sexuality? Or the fact that the dignity of others and our human vocation to love thus end up being less important than an obscure need to 'find oneself'? (Pope Francis, 2016 Amoris Laetitia)

From a Catholic perspective, marriage is a permanent and exclusive commitment between a man and a woman, who freely give themselves to each other in love and in so doing commit themselves to love and care for any children that may arise from their mutual love. Commitment, intimacy and passion vitalize and nurture covenanted love (Genovesi, 1996). Sexual intimacy is a sign of fully committed love. Outside the context of marriage, genital intimacy, however well intended, is not an expression of total self-giving. Marriage is also a public commitment. The two partners freely choose to enter into this partnership, this covenant. They say 'yes' to each other, to being there for each other and to working together to make God's creative love present in the world. They do this through their active participation in the community as committed partners and through bringing about new life through sexual intercourse. The Catholic perspective on marriage is that it should be treated as something permanent and exclusive in which divorce and extra-marital affairs have no place. Public commitment to a permanent and exclusive partnership of mutual co-operation and self-giving love provides the institutional and community basis for the trust necessary for the married couple to truly open themselves to each other. They are able to give themselves wholly to each other in the knowledge that there is a community who will support them in their decision when times are hard and assist them in the raising of their children.