"Love is sufficient of itself, it gives pleasure by itself and because of itself. It is its own merit, its own reward. Love looks for no cause outside itself, no effect beyond itself. Its profit lies in its practice. I love because I love, I  love that I may love. Love is a great thing so long as it continually returns to its fountainhead, flows back too it source, always drawing from there the water which constantly replenishes it. Of all the movements, sensations and feelings of the soul, love is the only one in which the creature can respond to the Creator and make some sort of similar return however unequal thought it be. For when God loves, all he desires is to be loved in return; the sole purpose of his love is to be loved, in the knowledge that those who love him are made happy by their love of him." St. Bernard

This is the heart of our relationship with God. The three divine Persons love each other for the sake of the other. God loves us for our sake, for our happiness. He doesn't need our love, for God is complete without us. He desires our love so that our love will not become dead for lack of response. His love is of such a nature that it calls forth the best from us for our fulfillment in him. Love is a mystery that only becomes clearer in the gift of love to the Beloved. When we truly love without conditions something happens within us. There is a sense of rightness, a sense of goodness. True love beings about union with the Beloved.