'Christianity is first and last Christ himself. It is not, ultimately, a collection of doctrines and laws, dogmas and regulations, but a reality which is there, and which is present in our lives ever anew: Christ and his grace, the reality of God which, in Christ, becomes our own reality . . . For Christ is God's will for our salvation made historical, made flesh; God's personal, loving will does not encounter man in some unattainable, intangible 'inner realm'; since Christ, since the One who became man, all grace is Christ's grace with a body, grace dependent on the historical event that at one particular space-time point in our human history the Word became man and was crucified and rose again . . . If anything was not assumed, neither was it redeemed . . . But everything has been assumed, for Christ is true man, true son of Adam, truly lived a human life in all its breadth and height and depth . . . And hence everything, without confusion and without separation, is to enter into eternal life; there is to be not only a new heaven but a new earth. Nothing, unless it be eternally damned, can remain outside the blessing, the protection, the transfiguration of this divinization of the world which, beginning in Christ, aims at drawing everything that exists into the life of God himself, precisely in order that it may thus have eternal validity conferred upon it. This is the reality of Christ, with constitutes Christianity, the incarnate life of God in our place and our time. A reality to which belongs the word; a reality in which all human reality is called to God and blessed.'
In the above quotation Rahner answers the question regarding the meaning of Christianity with some key christological convictions that express the core of his faith. Christology for him is not simply one theme among others; rather, it constitutes the heart of his theology. Karl Rahner, S.J. saw himself as a socius Jesu, a “companion of Jesus ” - the poor and marginalized one - and as a member of his religious order, the Society of Jesus.