Issues relating to people who are erotically attracted to someone of the same sex are complex. First of all, a word about language. In the past people spoke about homosexuality and 'homosexuals'. The latter expression tended to reinforce the idea of identifying the person with his or her sexual orientation. Today it is more common to talk about persons with same-sex attraction. This identifies such people as first of all persons with all that implies, and only secondarily refers to their sexual orientation. It is very common for some to use the acronym LGTBI (and sometimes other letters are added) to identify a group of people: Lesbians, Gays, Transsexuals, Bi-sexuals and Intersex. Sometimes they will be referred to as a community. However, there are many people who fall under one of these 'categories' who may resent being labelled in this way and are offended by it. It is best to avoid such labelling together with the presumption that all those who are same-sex attracted form part of this community. There is not one kind of experience of being same-sex attracted. For this reason definitions can be difficult. For example, some people experience transient same-sex attraction but it is not a permanent condition for them, so they would not generally be considered as part of the same group as those who would identify themselves as same-sex attracted persons. It is very important to realise this when dealing with young people who might be thinking they are erotically attracted to people of the same sex.
When it comes to the origins of same-sex attraction there is not a consensus. However, despite much popular opinion, the evidence does not support the thesis that it is solely genetically caused. That does not mean that biological factors do not play a part. Researchers have proposed that genetic, biological, cultural, social and/or developmental factors can contribute to some degree to the development of same-sex attraction. There would not appear to be one cause, nor does the cause appear to be the same for everyone. It certainly helps one's understanding to read some well-balanced scientific views on same-sex attraction.
The Church's teaching on same-sex attraction and homosexual acts cannot be understood outside the overall context of the teachings of meaning and purpose of human sexual expression as being about promoting the unitive love of a man and a woman and the openness of that union to new life (see above). A Catholic perspective, therefore, makes an important distinction between the person, that person's experience of being sexually attracted to members of the same sex and choices that person makes in response to this experience. Only the person's choices are free decisions and consequently only those personal choices can be morally evaluated (see the section on Morality and Conscience below). The experience of this attraction, and especially the person, who is created in the image of God and always loved and called by God, cannot be morally evaluated as good or bad, or right or wrong. Homosexual acts are considered morally wrong as is the case with all sexual acts that do not involve sexual intercourse in the context of marriage between a man and a woman. The reason for this is that such acts do not serve the proper purpose or ends of human genitals and human sexuality, namely, the unitive good of conjugal love between a man and a woman and the generative good of procreation. Persons with same-sex attraction must be respected as the persons they are. The Catechism of the Catholic Church says: 'They must be accepted with respect, compassion, and sensitivity. Every sign of unjust discrimination in their regard should be avoided' (CCC n.2358). Generally speaking, people are not responsible for their sexual attraction. They do not choose to be sexually attracted to members of the same sex. Since they do not choose, same-sex attraction cannot be evaluated as a moral decision. Therefore, one may not make moral judgements of a person because they experience this same-sex attraction. People with same-sex attraction should never be demonized, dehumanized, humiliated or shamed because of this attraction. We (The Synod on the Family) would like before all else to reaffirm that every person, regardless of sexual orientation, ought to be respected in his or her dignity and treated with consideration, while 'every sign of unjust discrimination' is to be carefully avoided, particularly any form of aggression and violence. Such families should be given respectful pastoral guidance, so that those who manifest a homosexual orientation can receive the assistance they need to understand and fully carry out God's will in their lives (Pope Francis, 2016 Amoris Laetitia). As with everyone else, people with same-sex attraction are called to live a life where their sexuality, including their sexual attraction, is integrated into the service of the good. All sexual acts, regardless of one's sexual orientation, are actions about which we are able to make choices and therefore are acts that can be morally evaluated. Sexual acts serve the good of the person and the community only in the context of the marital union. 'Casual homosexual sexual activity indulged in solely for the pleasure of the act can be as destructive and as meaningless and damaging to the human integrity of those involved as casual heterosexual sex' (Vardy, 1998, p. 218). The Church's teaching applies to everyone, heterosexually attracted or homosexually attracted alike. The proper context for the expression of sexual love is within the marital union understood as the life-long communion of two people of complementary sex which makes the two-in-one communion possible. The virtue of chastity (see below) calls us all to integrate our sexuality into our lives in such a way that we refrain from sexual expressions of love outside the context of marriage. The Church believes that those of same-sex attraction can do this as can people of heterosexual attraction. As with everyone else people of same sex attraction need community support. including support from the community of the Church.