Employing the riches of the Christian tradition, Karl Rahner developed a comprehensive theological vision that brought disparate doctrinal elements together as facets of a central mystery, the grace that is God's self-communication to the world. The heart of Rahner's theology is the divine self-gift evolving in history from creation to covenant to incarnation to vision and unfolding a “world of grace.” Rahner attempted to integrate the essentials of faith into a unified whole, drawing new life and unrealized meaning from the tradition. His vision toppled the neo-scholasticism that dominated Catholic theology since the mid nineteenth century and contributed to unleashing a Catholic theological renaissance. Rahner retrieved much that theology had come to overlook in its history of forgetting.

Influenced by Heidegger, Kant, and Maréchal, Rahner was rereading Scripture, the Fathers, and especially Aquinas, in light of the modern “turn to the subject.” In a radical inversion of Feuerbach, Rahner saw that if theology is anthropology, correlatively, anthropology is theology, since God’s incarnation forever united humanity and divinity.We cannot speak of God or humanity without at least implicitly speaking of both. The turn to the subject, then, is not inimical to Christian proclamation of human fulfillment as union with God. One finds in Christianity the fullest affirmation of the human as finite spirit open to holy mystery. In its thrusting toward this mystery the human person in freedom creates itself. Anthropology becomes the point of entry to the whole of theology. Theology will be taken seriously, Rahner thought, to the extent that it can show that humanity has to do with the question of transcendence.