Love is the basic vocation we all share. We begin with love, continue in love, and reach our fulfilment of love through, with, and in God when we die. The desire to be loved and to love, to be united with one another, is a deep-seated and natural yearning flowing from being created in Love's own image. God, whose Trinitarian being is to-be-in-relationship, invites us to a 'destiny of union with God and other(s) in self-giving love' (Coultier & Mattison III, 2010 p. 211)

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).

The link between this conception of love and with the notion of 'preference' helps us to see another important dimension of the Catholic understanding of love. Love is intimately interwoven with justice. With this in mind scholars have discussed and debated the precise nature of the love-justice relationship for many years. What is clear from all of these debates is that irrespective of whether love is prior to justice or justice is prior to love, or whether justice is a kind of love or love is a kind of justice, the two are inseparable. To truly speak of justice, one must talk of love and to truly speak of love, one must talk of justice. Justice without love is hard and calculating. Love without justice can become self-absorbed and unfocused. So when Catholic social teaching talks about a 'preferential option for the poor' it is talking about loving by doing justice and about doing justice with and for love. So too, in the context of interpersonal relationships, to love someone, to truly 'prefer' someone, is to make sure that all of your interactions are truly just. What is sought is the mutual good of both parties not simply one's own good. Mutual love also extends outwards to the wider community.

The Christian understanding of God is a Trinitarian one. All relationships are meant to mirror the relationality that constitutes the Trinity. All relationships are to be characterised by love, radical equality, mutuality, inclusivity and justice with mercy. God is a Trinity of Father, Son and Holy Spirit. This is not to say that there are three Gods. Rather this mystery gives expression to three 'persons' of the same divine being (substance). Three persons in one God. Christian mystics have contemplated this mystery for centuries. The central aspect of most of these reflections is how the idea of the Trinity helps us to understand what it means to say that God is love. The persons of the Father should not be understood to mean that God is male since God has no gender (CCC 370). God the Son or the Word becomes incarnate as a human being, Jesus of Nazareth. Together with the Spirit all three persons are necessary if God is not to be reduced to simply an unmoved mover, or some omnipotent power. These three persons make God understood as pure divinity, the greatest good, the most powerful power, fundamentally relational and personal. Moreover, God's fundamental relationality is defined not by power or violence or competition, but by love. This means that contrary to many other conceptions of divinity or of gods such as Deistic notions of God as divine clockmaker, the Christian conception of God makes relationship with the world and with human beings, and a genuine concern for the wellbeing and flourishing of the world and of human beings, fundamental aspects of God's very own existence. We say, therefore, that the Christian God is a personal God, who is actively engaged in and with human beings and their affairs in history. God cares. God must care. It is part of God's very nature. It is worth unpacking this notion of Trinity a little further because it helps to explain what it means to love, to 'see as God sees', to prefer as God prefers. The relationship is as follows. The Father begets the Son, and the Spirit proceeds from the Father and the Son. The relationship between the Father and the Son can be thought of as the relationship between the giver and the receiver of love and the reciprocation of the giver's love by the receiver. Out of love, the Son is begotten by the Father. The Son, in return, looks back with love to the Father. This mutual gaze of the Father and the Son, the giving and receiving of love, gives rise to the Spirit, a love that expands beyond the two into a genuine community of love. We can expand this understanding of relationality within God to explain the relationship between God and human beings. Just as the Father loves the Son, so God loves each and every human being. The Son reciprocates that love for the Father and so each human being is called by God to return God's love. This entails accepting with gratitude the gift of existence. It involves the realization that each individual is uniquely willed and loved by God. Finally, just as the Spirit flows forth from the love between the Father and the Son forming a Trinitarian Communion, so my love for my neighbour, my spouse, and my children, flow forth from God's love for me and my love for God forming a community of God, self and other. If I accept that God loves me, then I must also realise that God loves each individual. So when I see as God sees, when I love in the Christian sense of the word, I prefer the other person in the way that makes real God's preference for that person, a preference that God has for every human being. So to say that a Christian understanding of love is to 'see as God sees' is to say that in the other person I recognize someone who is like I am, but is not me. Nor is that person a product or an object of my creation or of my willing. Rather, that person is always an Other, a unique image of God, willed by God for his or her own sake. That person is loved by God. God's desire is for that person to share in the eternal love that is part of the communion of the Trinity.