Love cannot be fully defined, it would be a matter of the part (humanity) trying to observe the whole (God). Love is as elemental as God in the configuration of the Godhead. The Godhead loving itself (no creation or even Trinity yet), may even be free of the emotional elements of love, it is a love which is not dependent upon emotional satisfaction. When the persons of the Trinity are revealed, the personhood of God is revealed; along with its accompanying virtues and emotions of love.
Too often, human love grasps onto the satisfying emotions of love, to the exclusion of virtuous love. We accept love of virtue, so long as we are also emotionally satisfied. In our spiritual development we should reflect always on the elemental love of the Godhead and of the Trinity.