The Catholic perspective promotes human dignity, the essential worth or dignity of the human person as made in the image and likeness of God. Each human being is unique and unrepeatable and loved and called by God. This means that every human being, in every circumstance, is good. This is not to say that they are morally good. Our moral goodness or moral badness is based on the moral decisions we make. Rather, to affirm the worth or dignity of the human person is to affirm that it is a good thing that he or she exists, that his or her existence is desired by God and that his or her existence is worthwhile. The dignity of the human person is the foundation of a moral vision for society (United States Conference of Catholic Bishops, 2013). Catholic thinking about sexuality and relationships is based on this basic affirmation of the equal worth of all human beings.
The sanctity of life is one way of giving expression to this basic affirmation of the worth or dignity of all human beings. When the Catholic Church affirms the sanctity of life it affirms that it is good that a particular human being exists rather than the reverse. the existence of each human person is willed by God and human beings have no right to destroy that existence. To say that life is sacred is to say, no matter who you are, no matter what you have done, no matter what you will do, the simple fact that you exist as a specific human being is enough for you to be considered worthy of life, worthy of respect and worthy of those things that will help you to flourish rather than perish.
God has called us to flourish. God wants us to flourish. In a sense, flourishing is our human vocation. Human beings don't simply exist. Human beings can exist badly in circumstances that don't seem to be in tune with the idea that their existence is a good thing and that they are willed and loved by God. Such circumstances can lead to the death or perishing of human beings in both the literal and the figurative sense. Perishing in the figurative sense mean that spiritual life, mental well-being and physical health begin to wither and die. On the other hand human beings can exist well, living their lives in circumstances and ways through which they flourish. When we think about what it means to talk about human flourishing, we focus on the achievement of the fullness of our potential as human beings in all dimensions: physical, mental, spiritual and relational. The Catholic perspective promotes human flourishing in all its dimensions together with the making of moral choices in ways that contribute to, rather than threaten or undermine, this flourishing of the whole human person.
A Christian understanding of love can be defined as 'seeing as God sees'. The Greek word, which is translated as 'love', in the quote from 1 Cor. 13 above is agape. The word, which appears to be used only in the Bible and appears to connote a particularly Christian conception of love, has its root in the concept of 'to prefer'. Thus, we could understand love in this sense to mean a certain kind of preference or a way of preferring. When I say I 'love' something, I am saying that I 'prefer' that something, that I have a preference for that something. If I say, 'I love sunny days' you understand that I am expressing some sort of preference or appreciation or desire for sunny days. In interpersonal terms, then, to say you love someone is to express a preference for that person. You choose to see that person in a certain way. You choose to will the good of that other person. The Christian understanding of this love, of this way of preferring is described in 1 Cor. 13:4-87. In this letter of St Paul to the early Christian community in Corinth, Paul is giving the Corinthians some advice on certain issues affecting the community. He is saying that to be an effective Christian community certain things are important. These are the things that the Christian community at Corinth should focus on and make a reality in their community. Paul argues that love is more important than any other feature of the Christian community. It is more important than all the other charismatic gifts of the Holy Spirit such as speaking in tongues, prophecy and the like. (Love is more important than even apparently heroic actions such as giving up your possessions or your life. Love is more important than all of the other virtues, even faith and hope. In the end, all that will remain is love. Love is a special kind of preferring. Paul characterizes this special way of preferring as follows: Love is patient; love is kind; love is not envious or boastful or arrogant or rude. It does not insist on its own way; it is not irritable or resentful; it does not rejoice in wrongdoing, but rejoices in the truth. It bears all things, believes all things, hopes all things, endures all things (1 Corinthians 13:4-13). See Pope Francis' reflection on this Pauline text in Amoris Laetitia 90: 118 (2016) In the context of relationships and sexuality education this kind of love, this kind of preferring, defines how we should relate to each other at an interpersonal level as in the general notion of loving your neighbour as yourself. In particular this Pauline understanding of love can be applied to how husband and wife should relate to each other in the specific relationship between a man and a woman in the context of marriage. To illustrate how this might work, try replacing the word love in the text above with the word preferring. What this reveals is that love, in this Christian sense, is not selfish. To prefer is not to possess. Indeed, it is not really even about a 'preference' in the common English sense of something you like. Rather, it is about giving preference to the other, to the beloved. It is about concern for the flourishing, for the wholehearted living of the other, of the beloved one. When I say that I love sunny days, I do not make a claim on them, as if I control or own sunny days, as if sunny days are simply there for my pleasure. Rather, to say that I love sunny days is to be in wonder of sunny days for what they are—sunny, warm, bright. So too when we love someone in this Christian sense there is a certain unconditionality about that love. Our preference is for the person as a person, as he or she is, as the beloved, the one loved. It is about being in wonder of who that person is. In other words, love is about wanting what is good for that person. Love is about wanting that person to flourish, to realise the fullness of their humanity as made in the image of God, male or female. Love in the full sense of the word is a virtue, not just an emotion, and still less a mere excitement of the senses. The virtue is produced in the will and has at its disposal the resources of the will's spiritual potential: in other words, it is an authentic commitment of the free will of one person (the subject), resulting from the truth about another person (Wojtyla, 1981 p. 123).