1. As was explained above in question C, the Christian, like Jesus, is both human and divine. This is the basis of the relationship between divine and human goodness in Christian life explained in question E. In Christian life, the human and the divine are distinct but not opposed, united but not commingled.
2. Several serious consequences follow from confusing or commingling grace and nature. First, it becomes impossible to delineate the likeness of the Christian to Jesus and of Christian life to his life. Second, because the supernatural is made to appear an alternative form of human fulfillment as such, it seems that the price of holiness is a more or less drastic dehumanization. Third, considered in itself, the natural order appears incomplete and therefore lacking in autonomy; for example, a natural desire for heavenly beatitude is posited, and the supposition that there is such a desire raises endless, insoluble theological difficulties. Fourth, the Christian’s share in divine life tends to be reduced to a mere metaphor, so that it can be fit within the finite bounds of created human nature.
3. By pressing the likeness of the Christian to Jesus and of Christian life to his life as far as possible, chapters twenty-five and twenty-six will provide a map of the way of Jesus which avoids exaggerating (or denigrating) either its supernatural and other-worldly aspects or its human and this-worldly aspects (see 1‑G). The intention will be to do greater justice than was done by either classical moral theology or the new moral theology to the complex unity of Christian life as both human and divine, this-worldly and other-worldly. Chapter thirty-four will return to an explicit treatment of this point.
4. The make up of the Christian is, to be sure, not that of Jesus. Jesus is a divine person; all things are made through him, and he is before all else that is; with the Father and the Spirit, he is the creator. We are human persons; we are creatures. Jesus becomes man by his own choice; he assumes humanity. We become divine by being begotten by the Spirit, who by the Father’s will adoptively makes us members of the divine family.
5. The union of the divine and human in Jesus is hypostatic; that is, the two natures are united in his unique, divine person. In us, the union of divine and human cannot be hypostatic, for human personhood is finite and as it is given cannot include divine life. Divine life is in us as a disposition to fulfillment in divinity; it is the love of God which is poured forth in our hearts and inheres in us. Receiving this gift by faith, we act in faith both according to our divine love and according to our natural human love. Divine and human are thus united in the Christian dynamically, not hypostatically. Nevertheless, this union is real and is without commingling; likewise, the distinction of the divine and human in us is real and is without any opposition.
Jesus is one person with two natures; so are we. His humanity is assumed into the unity of his divine person. Our divinity is received into the unity of our human free choice. As Jesus is, so we are in this world (see 1 Jn 4.17).20 In considering the make up of the Christian and the make up of Christian life, this analogy must be carried through and taken seriously. If not, all sorts of difficulties arise analogous to those which arose in Christology in the early centuries of the Church.21
Of course, our make up is not exactly the same as that of our Lord. He is an uncreated divine person; we are created human persons. He is Son of God by nature, we children of God by adoption. But unlike ordinary cases of adoption, in which a person of human nature adopts a child of human nature, thus changing the child’s parentage but not its nature, God’s adoption of us makes us share in his divine nature. For all practical purposes, a human adoptive parent removes the adopted child from its natural family. But God does not remove us from our natural, human family. Thus God’s adoption of us endows us with the infinite riches of his goodness without requiring us to renounce the finite, but very real riches, of our human heritage.
6. This account of the Christian’s make up is of fundamental importance for understanding Christian moral principles. It safeguards the integrity of human goods, precluding any supposed need to negate the human in order to make way for the divine. Moreover, on this account the natural law remains valid for Christian morality, as is required by Catholic moral teaching. As chapters twenty-five and twenty-six will explain, Christian morality completes the morality of the natural law by specifying it, not by making extrinsic additions to it.
7. Furthermore, because by this account the Christian’s divine life by adoption is no mere metaphor, any tendency to think of grace as merely covering over sins is excluded. By reason of their real deification, Christians can live like Jesus in this world and hope with a well-founded hope to share fully in his eternal fullness.
20. The New American Bible translates 1 Jn 4.17: “Our love is brought to perfection in this, that we should have confidence on the day of judgment; for our relation to this world is just like his.” This translation makes “his” appear to have God for its reference and renders the passage irrelevant to the point for which I cite it. However, the exegesis of Spicq quoted in question C supports the use I make of the passage. Also see Wilhelm Thüsing, The Three Epistles of St. John, and Alois Stöger, The Epistle of St. Jude (New York: Crossroad, 1981), 83–84; Alfred Marshall, The R.S.V. Interlinear Greek-English New Testament (London: Samuel Bagster and Sons, 1975), 934 and 943.
21. An extensive treatise on the development of Christology and on the various heresies: Aloys Grillmeier, S.J., Christ in Christian Tradition, vol. 1, From the Apostolic Age to Chalcedon (451), trans. John Bowden, 2d ed. (Atlanta: John Knox Press, 1975); also J. N. D. Kelly, Early Christian Doctrines, rev. ed. (San Francisco: Harper and Row, 1978), 138–62, 280–343.