We cannot know whether we love God although there may be strong reasons for thinking so, but there can be no doubt about whether we love our neighbour or no.
St Teresa of Avila, The Interior Castle

The problem of this statement lies in the tortuous quality of so much human emotion. Jeremiah was only too correct when he lamented the deceit and moral sickness of the human heart (Jer. 17.9). St Paul, in a rather similar fashion, showed how we are so often governed by emotions contrary to what we desire in our times of decision (Rom. 7.19). There is a type of strong positive emotion, commonly called love, which is in fact an uncontrollable desire to possess another person, to overwhelm and take charge. Once this desire has been satisfied, the object of infatuation is likely to be imprisoned in a passionate embrace that prevents any further independent movement. This terrible state of affairs may continue indefinitely, depending entirely on the selfish needs of the "lover"; on the other hand, the object of this lustful desire may be summarily discarded like a piece of old clothing once the emotional attraction has faded. The love of Don Juan is of this character, and the emotional pain visited on the victim may be of suicidal intensity. (The matter has been further discussed in "The Wheels of Love".)

It seems evident that a love which has a strongly passionate component has to be treated with firm discretion. The test is its durability, and whether it allows the object of affection sufficient freedom to carry on his or her own life without interference. It is on this note that a more mature love can be discerned. It is a warm desire for fellowship, for mutual protection, and finally for union. It tends to grow in the breadth of satisfaction until the desire begins to fade away and the union becomes firm, even rock-like in commitment. And then love of a noble maturity flows between the two participants, and from them to an ever-increasing number of other people.

When we see love in this context, it is evident that St Teresa's certainty about our love, or our lack of it, for our neighbour needs careful qualification. But St John is equally emphatic: "If a man says, "I love God", while hating his brother, he is a liar. If he does not love the brother whom he has seen, it cannot be that he loves God whom he has not seen" (1 John 4.19-20). But immediately preceding this passage is the pivotal statement that we love because God loved us first.

In fact, you know that you are at least starting to love your neighbour when your heart, or inner being, opens to him or her, and compassion joins you to the person. There is a spontaneous giving of yourself to that individual, which is in fact the love of God flowing through you to him or her. The concept of flow is especially apt, because love is an uncreated energy of God, as is also the uncreated light described in 2 Corinthians 3.7-18. It is not associated with any emotional outpouring, but when it flows through us, it evokes a warmth of affection that not only changes our heart of stone into vibrant flesh, but also enlightens our mind, so that we can see much of what is invisible to the naked eye and incomprehensible to the native intellect. It is in this respect that we can know that we are deeply concerned about our neighbour, as the Good Samaritan was in his famous encounter with the robbed, assaulted traveller on the Jericho road. If we can see love in this context we will not be far from God at any time; for the more his love flows through and from us, the closer we are both to him and to our neighbour. The more we love God, the more does that love overflow to those around us. Conversely, if we love our neighbour in undemanding solicitude, we will draw ever closer to the knowledge of God. The all-important discipline is prayer; this brings us unceasingly close to God and his creation.

May I have, Lord, that steadfast attention to the work of the present moment that will make me ever aware of the needs of those around me, so that I may be an unfailing instrument of your love in whatever situation I may find myself.