"If any one says, 'I love God', and hates his brother, he is a liar; for he who does not love his brother whom he has seen, cannot love God whom he has not seen. And this commandment we have from him, that he who loves God should love his brother also." (1 Jn 4:20-21)
The theological virtue of charity is expressed in two dimensions: love of God and love of neighbour. In both these dimensions it is the fruit of the dynamism of Trinitarian life within us.
Indeed, love has its source in the Father; it is fully revealed in the Passover of the crucified and risen Son, and is infused in us by the Holy Spirit. Through it God lets us share in his own love.
If we truly love with the love of God we will also love our brothers or sisters as God loves them. This is the great newness of Christianity; one cannot love God if one does not love one's brethren, creating a deep and lasting communion of love with them.
Love should be extended to strangers and even to enemies.
In this regard, the teaching of Sacred Scripture is unequivocal. The Israelites were already encouraged to love one another: "You shall not take vengeance or bear any grudge against the sons of your own people, but you shall love your neighbour as yourself." (Lv 19:18) At first this commandment was restricted to the Israelites, but it nonetheless gradually takes on an ever broader sense to include the strangers who sojourn among them, in remembrance that Israel too was a stranger in the land of Egypt. (cf Lv 19:34; Dt 10:19)
In the New Testament this love becomes a command in a clearly universal sense: it presupposes a concept of neighbour that knows no bounds (cf Lk 10:29-37) and is even extended to enemies. (cf Mt 5:43-47) It remains linked to love of God: indeed the two commandments of love are the synthesis and epitome of the law and the prophets. (cf Mt 22:40) Only those who fulfil both these commandments are close to the kingdom of God, as Jesus himself stresses in answer to a scribe who had questioned him. (cf Mk 12:28-34)
Abiding by these guidelines which link love of neighbour with love of God and both of these to God's life in us, we can easily understand how love is presented in the New Testament as a fruit of the Spirit, indeed, as the first of the many gifts listed by St. Paul in his Letter to the Galatians: "The fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control." (Gal 5:22)
Theological tradition distinguishes, while correlating them, between the theological virtues, the gifts and the fruits of the Holy Spirit (cf CCC, 1830-32). While virtues are dispositions permanently conferred upon human beings in view of the supernatural works they must do, and the gifts perfect both the theological and moral virtues, the fruits of the Spirit are virtuous acts which the person accomplishes with ease, habitually and with delight.
These distinctions are not contrary to what Paul says, speaking in the singular of the fruit of the Spirit. In fact, the Apostle wishes to point out that the fruit par excellence is the same divine charity which is at the heart of every virtuous act. Just as sunlight is expressed in a limitless range of colours, so love is manifest in the multiple fruits of the Spirit.
Those who do not love their neighbour do not truly love God
In this regard, it says in the Letter to the Colossians: "Above all these put on love, which binds everything together in perfect harmony." (3:14) The hymn to love contained in the First Letter to the Corinthians (cf 1 Cor 13) celebrates this primacy of love over all the other gifts, and even over faith and hope. The Apostle Paul says of it: "Love never ends."
Love of neighbour has a Christological connotation, since it must conform to Christ's gift of his own life: "By this we know love, that he laid down his life for us; and we ought to lay down our lives for the brethren." (1 Jn 3:16) Insofar as it is measured by Christ's love, it can be called a "new commandment" by which the true disciples may be recognised: "A new commandment I give to you, that you love one another; even as I have loved you, that you also love one another. By this all men will know that you are my disciples, if you have love for one another." (Jn 13:34-35)
The Christological meaning of love of neighbour will shine forth at the second coming of Christ. Indeed at that very moment, it will be seen that the measure by which to judge adherence to Christ is precisely the daily demonstration of love for our neediest brothers and sisters: "I was hungry and you gave me food…" (cf Mt 25:31-46)
Only those who are involved with their neighbour and his needs concretely show their love for Jesus. Being closed and indifferent to the "other" means being closed to the Holy Spirit, forgetting Christ and denying the Father's universal love.
Pope John Paul II