God is love: A basic Christian claim

What do Christians mean when they say that God is love? How do we answer that question in a dialogue between Muslims and Christians, which is to say, in a tension-filled intellectual space of wrestling to understand and articulate our similarities and differences with regard to what it means to love God and neighbor?

To answer this question briefly, it is best to go back to 1 John 4:7-12:

Beloved, let us love one another, because love is from God; everyone who loves is born of God and knows God. Whoever does not love does not know God, for God is love. God's love was revealed among us in this way: God sent his only Son into the world so that we might live through him. In this is love, not that we loved God but that he loved us and sent his Son to be the atoning sacrifice for our sins. Beloved, since God loved us so much, we also ought to love one another. No one has ever seen God; if we love one another, God lives in us, and his love is perfected in us.