Why a Christian is able to love stems from the prior love expressed from God to them (We love because he loved us first. 1John 4.19). Further, 1John speaks almost as much about Love as 1Cor.13. Consider the various facets of love: The practice of righteousness (Everyone who does not practice righteousness—the one who does not love his fellow Christian—is not of God. 3.10b) The gospel message (For this is the gospel message that you have heard from the beginning: that we should love one another. 3.11). Assurance ( We know that we have crossed over from death to life because we love our fellow Christians. 3.14a). The commandment (Now this is his commandment: that we believe in the name of his Son Jesus Christ and love one another. 3.23). Love originates from God (Dear friends, let us love one another, because love is from God. 4.7a). Love shows evidence of knowing God (everyone who loves has been fathered by God and knows God. 4.7b). Loved caused Jesus to pay for our sins (In this is love: not that we have loved God, but that he loved us and sent his Son to be the atoning sacrifice for our sins. (4.10). It displays God’s indwelling (If we love one another, God resides in us, and his love is perfected in us. 4.12b). Love is knowable and trustworthy (And we have come to know and to believe the love that God has in us. 4.16a). God is love (God is love, and the one who resides in love resides in God, and God resides in him. 4.16b). Love is able to be perfected and it inspires confidence (By this love is perfected with us, so that we may have confidence in the day of judgment, because just as Jesus is, so also are we in this world. 4.17). Love erases fear (There is no fear in love, but perfect love drives out fear. 4.18a). [NET Bible]
Here are Don Carson’s thoughts on 1Cor. 13:
ALTHOUGH 1 CORINTHIANS 13 FORMS part of a sustained argument that runs through chapters 12–14, the passage constitutes such a lovely unit with so many wonderfully evocative lines that it has called forth countless extended treatments. Today I shall reflect a little on the first three verses.
This text does not say that love is everything and that the other things mentioned—speaking in tongues, the gift of prophecy, an ability to fathom mysteries and all knowledge, a faith that can move mountains, self-denying surrender of all possessions for the sake of the poor, and suffering a martyr’s death—are nothing. Rather, it insists that those things are utterly insignificant unless they are accompanied by love. Love does not displace them; its absence renders them pointless and ultimately valueless.
This paragraph is calculated to abase the arrogant. History offers sad examples of people who have become proud of their gift of tongues, of their prophetic gift, even of their philanthropy and self-sacrifice. But it is a contradiction in terms to be proud of one’s love, in any Christian sense of love. Perhaps that is one of the reasons why these other virtues are destroyed if unaccompanied by love.
One of the most striking features of this statement about love is how it rules out of bounds one of the definitions of love that still persists in some Christian circles. They say that Christian love does not belong to the emotional realm, but is nothing other than an unswerving resolve to seek the other’s good. That is why, they say, love can be commanded: one may thoroughly dislike the other person, but if one conscientiously resolves upon his or her good, and acts accordingly, it is still love. Quite frankly, that sort of casuistry is reductionistic rubbish. What has just been dubbed “love” is nothing other than resolute altruism. But in these verses Paul firmly distinguishes between altruism and love: “If I give all I possess to the poor and surrender my body to the flames” (1 Cor. 13:3): here are both altruism and self-sacrifice, but Paul can imagine both without love. So love must be something other than, or more than, mere altruism and self-sacrifice.
It may be difficult to provide a perfect definition for Christian love. But it is not difficult to find its supreme example. Christ’s love for us is not grounded in our loveliness, but in his own character. His love is not merely sentimental, yet it is charged with incalculable affection and warmth. It is resolute in its self-sacrifice, but never merely mechanical self-discipline. If we wish to come to terms with the apostolic depiction of Christian love as “the most excellent way” (1 Cor. 12:31b; see also the meditation for October 11) that all believers must follow, we need only imitate Jesus Christ.