God Is Love

We must understand what God's love is, before we can understand the union of God and man in love. And in doing this our attention is first arrested by the declaration of the Scriptures, — a declaration which is worthy of the particular notice of Christians,— that "God is love." It would be difficult to find a parallel form of expression. It is not anywhere said of God, so far as we recollect, that he is omniscience, or that he is omnipresence. It is true that the attributes of omniscience and omnipresence are essential to him as an infinite existence; but it should always be remembered that God is something more than infinity. There must be something beyond and above infinity, which shall baptize it with the character of goodness; otherwise there is no God. "God is Love."

God is love by essence.  That is to say, love is forever and unchangeably essential to his existence  as God. He was not at first, as some may be led to suppose, a mere percipient being, having all knowledge, who formed conjecturally an idea of love, came to the conclusion that it was a good and desirable thing, and then added it as an accessory to his original existence. On the contrary, God always had a heart; always had a true and effective sensibility, operating, by an eternal law of action, in the line of right and goodness. And if, by universal consent, the heart takes the precedence of the head, — if no greatness of intellect can elevate and save a man who has evil and depraved affections, — then God cannot be what he is, the infinitely desirable and infinitely good, without love as the central and leading element, the basis and the completion of his character.

— adapted from A Treatise on Divine Union (1851) Part 4, Chapter 2.