Gregory of Nyssa: "I also ask: Who has known his own mind? Those who think themselves capable of grasping the nature of God would do well to consider whether they have looked into themselves .... " For Gregory, not only is the nature of God himself a mystery to us, but as human beings created in God's image, we also remain a mystery to ourselves. My concern with much modern theology is precisely that it has lost a great deal of this sense of mystery. Modern theology's problem is its rational confidence - and thus, ultimately, its pride.