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).

Though most human beings are either male or female, and most human beings identify as such, there are some human beings who do not, or do not feel that they fall into either of categories, male or female. For some, this arises from genetic or biological divergence from the norm. For others psychological factors have an influence on perception of gender identity. The gender identity of others is influenced by a combination of biological and psychological factors. Examples include Sex Chromosome Aneuploidy, Intersex, and Gender Dysphoria or Transsexualism. As with all instances in which people feel like their situation (whatever that may be) is unusual or outside of what is 'normal', and especially where they associate this feeling of being unusual or outside of what is 'normal' with potentially negative treatment by others, these situations are often a struggle for the people who experience them and for those close to them. What will people think of me? Will anybody ever be able to love me? Will I be able to live a 'normal' life? These are some of the questions that people struggling with their sexual identity might ask. Indeed, they are questions that we all ask when we feel like we are 'not normal' or when we are deciding whether to do something that is 'not normal'. They are questions that arise from a fear of exclusion, or from being deemed less worthy of respect, care, love and justice. It is a fear that most people experience at some time in their lives, but a fear that for some people is a constant companion. These feelings are further exacerbated when we feel like we did not choose to be this way or to be in this situation. From a Catholic Perspective, the first and most important thing is to reaffirm that all human beings are created fundamentally equal in the image of God, worthy of equal respect, care, love and justice. In moral terms our being human is prior to our being a man or a woman. Consequently, no person who experiences a situation in which they feel they are 'not normal' should ever be made to feel like they are 'not worthy' of the respect, care, love and justice that is due to every human being by virtue of their being human. In particular they should never be made to feel like they are not respected, cared for, loved or treated justly. Bullying, teasing, violence, exclusion and any other kind of demonizing or dehumanizing treatment is never acceptable from a Catholic perspective. How an individual concretely deals with working out his or her sexual identity in these complicated situations is not something that should be taken lightly or treated flippantly. As we shall see below, sexuality is an important part of who we are as human beings. Taking sexuality seriously is part of what it means to live life whole-heartedly. Effective support for a person with regard to their sexuality is more likely to be achieved in a supportive environment in which emotional, intellectual, physical and spiritual support are at hand and understanding, and guidance are made available in a sensitive and dignity-affirming manner. However one resolves one's sexual identity, and one's identity as a person, one is always called upon to love responsibly and chastely as described below. Yet another challenge is posed by the various forms of an ideology of gender that 'denies the difference and reciprocity in nature of a man and a woman and envisages a society without sexual differences, thereby eliminating the anthropological basis of the family. This ideology leads to educational programmes and legislative enactments that promote a personal identity and emotional intimacy radically separated from the biological difference between male and female. Consequently, human identity be- comes the choice of the individual, one which can also change over time'. It is a source of concern that some ideologies of this sort, which seek to respond to what are at times understand- able aspirations, manage to assert themselves as absolute and unquestionable, even dictating how children should be raised. It needs to be emphasized that 'biological sex and the socio-cultural role of sex (gender) can be distinguished but not separated'. n the other hand, 'the techno- logical revolution in the field of human procreation has introduced the ability to manipulate the reproductive act, making it independent of the sexual relationship between a man and a woman. In this way, human life and parenthood have become modular and separable realities, subject mainly to the wishes of individuals or couples'. It is one thing to be understanding of human weakness and the complexities of life, and another to accept ideologies that attempt to sunder what are inseparable aspects of reality. Let us not fall into the sin of trying to replace the Creator. We are creatures, and not omnipotent. Creation is prior to us and must be received as a gift. At the same time, we are called to protect our humanity, and this means, in the first place, accepting it and respecting it as it was created (Pope Francis, 2016 Amoris Laetitia).