What does it mean that God is love? Well from how I understand it, after reading the first couple of chapters of C.S. Lewis's The Problem of Pain, is that God is and always has been loving himself. For us to love ourselves it is looked down upon, at least to love only ourselves. For God though it is perfectly fine for him to love himself because he is the greatest thing in the universe. He is the most worthy to be loved of all beings in existence. So for him to love something else would be tantamount to calling that thing the greatest thing in existence. Now I don't mean that he can't love us because he certainly can, but he loves us because he died for us and covered us with himself, so by loving us under those conditions, he's still loving himself. (This might be off so please correct me if so).
Since God is trinitarian in nature he has been able to have a relationship even before there were creatures for him to have a relationship with. The father can love the son, the son can love the father and the holy spirit can love them both, and so on. Now I'm saying this in language that implies there is more than one God, but don't get me wrong, God is ONE. I think part of the mystery of God is understood by married couples. Though they are two, they become one. God is in perpetual oneness with himself.
Since God is the greatest thing to be loved, Jesus came to earth and showed us how to do the most important thing in the world, love God. He knows what is best for us and that is himself. Because of sin we were separated from the privilege of loving God. Jesus made that wonderful and necessary thing possible again and in doing so he was also loving God. By obeying his will.
People, since they are made in the image of God, try to get people to love them the same way that God tries to get people to love him. If you ever listen to a rapper, rapping about himself, he puffs himself up, he makes huge statements about himself, statements with no basis or purpose except to make him look good. God does the same thing, but his statements have a basis in a firm foundation and they have a high purpose, to make God glorious. It's OK for God to be selfish because he is the only self perfect enough to also have the wisdom to be selfless. See, the reason Jesus is so hard to imagine as God's son is because God is so much higher than us. He's so much more than us. He has justification for being selfish and yet he, as Jesus, came to earth and became the exact opposite that he has every right to be.
I thank God that I am counted among those able to talk to him. If it wasn't for his infinite effort to bring us into a right relationship with the father, I wouldn't even be able to breathe anymore. God's mercy spared my life and his grace gave me the gift of a beautiful friendship with the one who made me. Thank you Jesus for your love.