Four Loves by C. S. Lewis
Introduction
Lewis distinguishes between Gift-love and Need-love. Gift-love is when a person does something that is a sacrifice with no expectation of return. Need-love is more like what happens when a frightened child is comforted by a parent. Lewis was prepared to disparage the later, but as he pondered the topic, it became way more complicated. He realized that our love for God is largely, if not entirely Need-love.
He notes that we need to be careful to not let the truth that God is love come to mean the converse, i. e. love is God.