In light of this ideal of marriage the separation of a married couple is always seen as something undesirable. People who have been through such a separation know from experience how undesirable separation is. No one should enter into marriage expecting its break down and the consequent separation of the couple. Indeed, thinking like that may even call the validity of the marriage into question. Most people, when they get married, really do believe, or at least hope, that they will live with and love each other for the rest of their lives. This is why, when, for many reasons, things don't work out it is regarded as tragic. Of course, at the time of separation, the separation may indeed be desired and necessary as in cases of domestic violence or infidelity. The Catholic perspective, whilst upholding the ideal on the one hand, nonetheless accepts human failings on the other. In such cases, where, despite support of the community separation is necessary, the Catechism of the Catholic Church states: 'If civil divorce remains the only possible way of ensuring certain legal rights, the care of the children, or the protection of inheritance, it can be tolerated and does not constitute a moral offense.' (CCC Article 2383)

Genital Sexual intercourse between a man and a woman has the potential to realise two good things, the unity of the couple and new life. And these two things cannot be separated from each other without diminishing the goodness of sexual intercourse. That is why the best place for sexual intercourse to occur is in the context of marriage. First, genital sexual intercourse is good because it is unitive. The two people grow closer together and become more unified through the extremely intimate act of penetration and ejaculation in the vagina. Sexual intercourse in this sense is not about selfish pleasure but about the complete gift of oneself to the other. Two become one, become unified as one flesh, one mind, and in a certain sense, one spirit. The act of genital sexual intercourse is the culmination and a sign of the trust and love that the two have for each other and their commitment to the idea that God wants a woman and a man to be partners in life, to grow together. Through sexual intercourse the bond of self-giving mutual commitment to each other is renewed and strengthened. But this unitive dimension must also be generative if it to be truly unitive, self-giving, committed, trusting, open to new life and conformed to God's will for humanity and for the couple themselves. Second, genital sexual intercourse is good because it is generative. Put simply, genital sexual intercourse brings about new life. But the meaning given to sexual intercourse in the Catholic perspective is deeper than simple procreation. Clearly, if any two fertile people have sexual intercourse a child could result. The Catholic perspective, however, holds that sex simply for the sake of producing children does not adequately represent God's intended purpose for sexual intercourse because it does not take the unitive dimension into account. The unitive dimension of sexual intercourse emphasises the importance that sex has for humans not merely as a means of reproduction but as a means for fostering loving, trusting and committed relationships that are best suited to raise children. Put simply, a loving committed couple (unitive dimension) is better able to provide a stable and loving environment to raise children (the generative dimension). Moreover, the generative or creative dimension is not limited simply to the biological production of new human beings. Two people who love each other unconditionally and who foster that love through the unitive act of self-giving sexual intercourse are more likely to be open, inclusive and loving towards others. Such a couple are more likely to be committed to working for the good of the community since they are able to rely on the strength that comes from being supported by a loving, trusting, and committed partner.

A Catholic perspective acknowledges that not everyone will marry and indeed that not everyone needs or wishes to get married and start a family. A person may also choose personal fulfilment through living life as a single person or as a person who has chosen some sort of religious profession in direct service to the Church as is the case with Religious Sisters and Religious Brothers and with Priests. There is further consideration of these important and valid ways to live out one's identity as a human person below.

Saint John Paul II (1981) recognized the irreplaceable importance of the family, not only to the individual, but also as the gift that it represents to society at large. The Pope emphasized that the family is both the setting for physical nurturing and the privileged place where children are educated in all aspects of what it means to be human (Diocesan Department of Religious Education, 2005 p. 76). A committed and secure marriage partnership which is supported, supportive, and loving remains the best environment for the upbringing of children. From a Catholic perspective, the family includes mother, father and children, extended family of grandparents as well as aunts, uncles and cousins. Beyond these family ties though the family is about society as a whole. The first experience of society that we have as children is in the family context. The family is where we learn to engage with other people. The Catholic perspective sees families as both inwardly focused and outward-looking engaging with society and taking an active role in transforming society by making God present. In this way, families are opened up to 'the disruptive but ultimately Christ-bearing presence of others, especially others in need' (Coultier and Mattison, 2010, p. 222). The family in turn is what the Second Vatican Council, in Gaudium et spes, calls a domestic church, which, as a sign of Christ, brings God to the world through service to society beyond the confines of the nuclear family. 'The Truine God is a communion of love and the family is its living reflection' (2016 Pope Francis, Amoris Laetitia 11). A married couple who experience the power of love know that this love is called to bind the wounds of the outcast, to foster a culture of encounter and to fight for justice. God has given the family the job of 'domesticating' the world and helping each person to see fellow human beings as brothers and sisters (2016 Pope Francis, Amoris Laetitia).

The single way of life is a characteristic of a wide variety of states of life in our culture. Among these states of life are the temporarily or permanently single, the divorced, the separated and the widowed (United States Conference of Catholic Bishops, 1991 p. 94). Single persons who seek to live a life marked by maturity maintain a careful balance between a healthy independence, with a reasonable degree of privacy and freedom and the need for love, including genuine belonging (United States Conference of Catholic Bishops, 1991 p. 94). Each of us is called to be sexually responsible and chaste in whatever vocation we discern (United States Conference of Catholic Bishops, 1991 p. 27).