1. The new covenant replaces the old. Jesus “has obtained a ministry which is as much more excellent than the old as the covenant he mediates is better, since it is enacted on better promises. For if that first covenant had been faultless, there would have been no occasion for a second” (Heb 8.6–7). A central theme of St. Paul’s Epistles to the Romans and Galatians is that God’s redemptive plan is accomplished, not by the law, but only “through faith in Jesus Christ for all who believe” (Rom 3.22; cf. Gal 3.19–29). Yet the new covenant is not a new beginning of God’s redemptive work (see DV 3–4). Jesus does not abolish, but rather fulfills, the law and the prophets (see Mt 5.17)—that is, the requirements and promises of the old covenant.9 As St. Thomas Aquinas points out, the community of the old covenant is a shadow of the communion realized in the Church of Christ (see S.t., 1–2, q. 107, a. 2; cf. Col 2.17).
2. As was explained (in 20‑G), God includes human cooperation in his redemptive work in order to preserve and enhance the dignity of fallen humankind even as he renews creation by his divine act of re-creation. Including human cooperation in his plan, God began by allying himself with human persons as they were, affected by sin and its consequences. For fallen men and women, the initial covenant relationship could not be perfect. As sinners, they were inevitably ambivalent toward God; as members of a humankind divided by sin, they were necessarily members of one human group locked in conflict with other groups. As chapter nineteen explained, God’s plan for humankind includes both integral human fulfillment and a share in divine life. Fallen persons could not at once grasp perfectly either of these realities. The law of the old covenant served as a monitor to educate those to whom it was given in preparation for humankind’s mature relationship with God in Jesus (see Gal 3.23–26).
3. The Incarnation of the Word is the key to God’s redemptive plan. (Here this fact is taken as a starting point; its fittingness will be clarified to some extent by what follows.) In his human life, the Word justifies fallen humankind by his perfect obedience to the Father, which calls for the response of the divine act of re-creation begun in Jesus’ resurrection, and forms the divine-human communion which God planned from the beginning (see Eph 1.7–23; Phil 2.6–11; Col 1.19–22).10 As man, the Word Incarnate needed a community and culture in which to be born. As chapter twenty-three will show, Jesus lived his life on earth only by understanding himself in terms developed in prior salvation history. Just as Mary was providentially prepared to be the mother of the Word made man, the old covenant providentially prepared Israel to be his nation (see Rv 12.1–5). Thus, before the perfect covenant God established with humankind in Jesus, an imperfect covenant was needed to shape the culture which humanly formed him.11
The Word Incarnate is not simply a man of his culture, for God created this culture, just as he wished it, to serve as a medium of his work of revelation. God relates history to his own saving purposes (see Rom 11.30–32). The center of salvation history, the Incarnate Word, is not cast adrift in the stream of human history. Jesus completes what God all along intends (see Jn 19.28–30; 2 Cor 1.20; and all the New Testament references to the fulfillment of the Scriptures). Rather than Jesus being reducible to his culture, his culture is more appropriately reduced to him.
4. In sum, the central reason for the imperfection of the old covenant is that God simply could not complete his redemptive work all at once.12 For the sake of the human cooperation included in his plan, the old covenant had to be a preparation for the fulfillment of God’s promises in Jesus. Necessarily imperfect, the old covenant could not by itself justify fallen humankind. Those subject to the law of the old covenant could be saved by God’s grace and by faith. But that law itself, though it made God’s people acutely conscious of their sinfulness, did not give them power to live good lives (see Rom 3.20; Gal 3.21–24).
5. Fundamentally, the new covenant perfects the old in a way that goes beyond its human aspects to God’s giving us a share in his own divine life. The people of the old covenant was genuinely and closely allied with God. Yet in a very real sense, in his absolute transcendence God remained a foreign power. A share in the Spirit of God was promised and hoped for, yet it was not given by the law and the way of life it shaped. The old covenant’s inadequacy to heal humankind’s alienation from God had to be overcome by a covenant which established intimate personal communion with him. Jesus established this new covenant. In it, God does dwell with humankind, and men and women become his friends, even his children (see Jn 1.12–18; Rom 8.14–17; Heb 8.6–13). The promised Spirit is given, and by his power God’s children can live not only humanly good but even supernaturally holy lives (see Rom 8.1–17).
If one might ask how Man even at the beginning could have conceived of sharing in divine life in a way that made it clear that this is truly worthwhile and involves no infringement on human interests, one certainly must ask how sinful Man could have conceived of such a thing. The Incarnation of the Word shows how this can be done. In Jesus God becomes humanly accessible (see S.t., 3, q. 1, a. 2).
Even at the beginning, Man must have stood in awe of God. Sinful men and women hide from him in guilty fear. Although he seems friendly, might his friendship not be withdrawn, with dire consequences for humankind? The Incarnation of the Word disposes of this difficulty. There can be no suspicion now that God involves himself in the human either sporadically or with dubious intentions, for by becoming one of us he himself has entered lastingly and unreservedly into the human situation.
Even the best of those chosen by God, an Abraham or Moses, was himself enmeshed in sin. Established on such a person, a community of friendship with God always remained unstable. With the Incarnation of the Word, however, divine life becomes part of creation and can no longer be expelled. God’s Spirit becomes present in creation in a new and personal way, the Word Incarnate being, as it were, a conduit through which the Spirit flows permanently into the created world.
6. Since the plan of God for divine-human communion, described in chapter nineteen, could not be revealed at once to the men and women of the old covenant, their cooperation in God’s redemptive work necessarily was limited by hope for success in their pursuit of objectives in this world: the inheritance of the promised land, many descendants, national greatness, and so forth. In a humankind divided by sin, the covenant community had to be one group; other human groups inevitably were their competitors and foes.
7. Under these conditions, it is understandable that those under the old covenant tended to make certain mistakes. Not all the elements of integral human fulfillment seemed to them as important as those goods whose realization they sought. The implications of Yahweh’s unique divinity and universal lordship did not easily transform the attitude of his people toward the remainder of humankind.
8. The fact that those under the old covenant were made acutely aware of sin yet not enabled to live holy lives had certain consequences. The relationship the old covenant formed was unstable on the part of Israel. Not only its sacrifices and sin offerings, but the covenant itself, needed renewal (see Heb 8.7–13; 10.1–18). Reverencing the law but not fulfilling it, men and women were tempted to try to lessen their responsibilities by treating as adequate a certain manageable set of outward performances. As Jesus’ conflicts with Pharisees and Zealots make clear, this legalistic mentality led to a false conception of evil, as if it were a positive reality to be avoided by precautions, isolated in certain classes—“sinners” and “pagans”—or destroyed by the violence of war. The apparent need to choose between some elements of human good and friendship with God was inevitable for fallen humankind and not wholly overcome by the old covenant.
The prophets longed for a better age in which friendship with God and complete human fulfillment would coincide. In such an age all the earth would know God (see Is 11.9). His pardon would be effective and would give everyone the power to live rightly (see Jer 31.31–34). Everlasting justice would be introduced (see Dn 9.24). The nations would come together at the Lord’s holy mountain (see Mi 4.1–3).
The need was felt for a better type of redemptive community than that established by the old, restrictive covenants: The new covenant must be open to all men and women. Furthermore, while dealing with evil as a reality, the community must not try to set aside some part of the good things made by God as if evil were peculiarly present in them nor may it treat those involved in sin as enemies to be destroyed. Only in such a new covenant could faithfulness to God and love of all human fulfillment coincide. In a world marked by the reality of sin and its consequences, however, the lives of truly good people are at the mercy of those who persist in evil. How can anyone live in such a world without resorting to the evils necessary to cope with it?
There is only one possibility. Members of the new redemptive community must have solid assurance that they will really be fulfilled by being faithful to God and to their own integral fulfillment. If this happy outcome cannot be realized in a world broken by sin, however, it could be perfectly realized in another world. The solution to the problem thus is for God to establish his perfect communion of friendship, his kingdom, as a reality not of this sinful world. Men and women living in this world will be invited to live also in the invisible kingdom and for the sake of fulfillment there. Yet a real bridge between this world and the invisible community will be needed, together with sufficient grounds for confidence that the invisible is not a myth.
The Word, eternally with God and a coprinciple of creation, “became flesh and dwelt among us” (Jn 1.14). God and his love became visible; a common life of divine and human persons was inaugurated, involving vastly greater intimacy between God and human beings than under the law of Moses. Jesus is the bridge between this broken world of human experience and the new creation, free of sin, which is being built up with him as its head (see S.t., 3, q. 26).
9. Jesus, being both God and man, shows that there is no need to choose between human good and friendship with God. Moreover, the eternal kingdom proclaimed by the gospel provides an object of human hope sufficient to motivate Jesus’ disciples to follow him lovingly, for the kingdom includes all the things for which a good person would long. Jesus makes it clear that his kingdom is not of this world and that it is a more inclusive reality than anyone previously could have imagined. Limitations on openness to various human goods, set by the law of the old covenant and by its misunderstanding, are overcome. The boundaries of the covenant community are extended to include all nations, so that the new covenant can coincide with the entire community of humankind, to whose integral fulfillment moral truth points.
10. The grace of the Holy Spirit, given through Jesus, supplies the power to overcome sin and live a genuinely holy life. Not conceived legalistically, the law of the new covenant is primarily interior (cf. S.t., 1–2, q. 106, aa. 1–2). Former moral compromises, such as permission for divorce, can be set aside (see Mk 10.2–12). The full requirements of moral truth for human fulfillment, not merely a legalistic minimum, can be met. Evil is more easily understood as the privation it really is, and evil is overcome in the only way it can be—as Jesus does, by healing love for those mutilated by sin and its consequences. Because it really overcomes sin, the new covenant in Jesus’ blood is made once for all and is everlasting.
11. In conclusion, the new covenant perfects the old primarily by establishing intimate divine-human communion through the God-man, Jesus Christ (see appendix 1). This communion in divine life has implications for human moral life and bodily life. Restored to friendship with God, those who enter into Jesus’ covenant are enabled to live upright lives. Although in this fallen world such lives remain difficult and seem humanly unrewarding, those who live in Jesus can be good persons in this world and can hope for the fulfillment their goodness deserves when it is answered by God’s re-creative act, begun in Jesus’ resurrection.
12. The moral implications of the new covenant, briefly described here, will be articulated in detail in chapters twenty-three through twenty-eight. The central principle of what follows is this: In his human life, Jesus deals with evil as a good man and child of God should. In doing this, he not only shows us how to live good human lives in the fallen world, but makes it possible for us to do so. He does this by making his own redemptive action present to us, so that our lives can be lived in cooperation with God’s redemptive work accomplished in him.13
A true man, yet free of sin, the Incarnate Word shows what human life in a sinful world ought to be. No one who believes in him can suspect his motives; they are entirely pure. He adds immeasurably to creation, to the glory of God, by manifesting God’s goodness and love in an unprecedented fashion. He carries on God’s redeeming work, not only by an almighty fiat from above but also by human action (see S.t., 3, q. 46, aa. 3, 12; q. 47, aa. 1–2). Proceeding in this way, the Word Incarnate becomes a potential friend to all other men and women. We can love and trust him as we can no one else. We can ally ourselves with him. And insofar as we do this, our sinful existence can be greatly reformed in our personal relationship with him, and our good acts can contribute to a worthwhile cause: his redeeming work (see S.t., 3, q. 8, a. 1; q. 69, a. 5).
As we shall see, it is almost impossible for a truly good human life in this sinful world to appear fulfilling. Jesus’ life, considered as objectively as possible, hardly seems so. If we believe in him, however, we look beyond his earthly life. We see that, while he lived a very restricted existence and died a miserable death, he was at the same time bringing into reality the human dimension of the heavenly fulfillment of which he is the first principle (see Col 1.15–22).
By his Incarnation and life among us, the Word of God provides us with the model of the Son of Man sharing gloriously in divinity. Looking to him, we are confident that our own lives, however compelling contrary appearances might be, are not wasted when our good efforts fail, not defeated when evil prevails, not ended when death comes. Thus we can be confident that it is not vain to choose rightly, for neither the inevitable self-limitation which comes with choosing nor the suffering which comes with choosing rightly in a sinful world will last. Really though invisibly, fulfillment in a communion of love is already ours. We rejoice in hope.
9. False notions of opposition between the Old Testament and the New Testament, between Matthew and Paul, are firmly set aside by careful exegetical work. See, for example, A. Feuillet, “Loi de Dieu, loi du Christ et loi de l’Esprit d’après les epîstres pauliniennes: Les rapports de ces trois lois avec la Loi Mosaique,” Novum Testamentum, 22 (1980), 29–65.
10. Arianism and present theological opinions like it in denying that Jesus is God have the practical significance of denying that by communion in Jesus Christians truly are united with God: Alasdair I. C. Heron, “Homoousios with the Father,” in The Incarnation: Ecumenical Studies in the Nicene-Constantinopolitan Creed, A.D. 381, ed. Thomas F. Torrance (Edinburgh: Handsel Press, 1981), 58–87. The explanation of redemption on the basis of the Incarnation of the Word and the obedience as man of the Incarnate Word already is found in the recapitulation theory of Irenaeus: J. N. D. Kelly, Early Christian Doctrines, rev. ed. (San Francisco: Harper and Row, 1978), 170–74; more fully, with useful references: Andrew J. Bandstra, “Paul and an Ancient Interpreter: A Comparison of the Teaching on Redemption in Paul and Irenaeus,” Calvin Theological Journal, 5 (1970), 43–63.
11. See Pierre Grelot, “Relations between the Old and New Testaments in Jesus Christ,” in Problems and Perspectives of Fundamental Theology, ed. René Latourelle and Gerald O’Collins, trans. Matthew J. O’Connell (New York: Paulist Press, 1982), 186–99. It is an error to contrast the old and new laws as if the old concerned only outward behavior and the new only interiority. The precepts of the old law called for inner holiness; the new law also has an outward aspect: Edward Kaczynski, La legge nuova: L’elemento esterno della legge nuova secondo S. Tommaso (Rome: Francescane, 1974).
12. For an excellent, brief account of the limitations of the morality of the old covenant: L. Johnston, “Old Testament Morality,” Catholic Biblical Quarterly, 20 (1968), 19–25. For an introduction to the historical evidence of the actual situation of the people of the old covenant: William Foxwell Albright, From the Stone Age to Christianity: Monothesism and the Historical Process, 2d ed. (New York: Doubleday Anchor Books, 1957), 200–333.
13. Thus, Jesus is not a new lawgiver, a new Moses, but is the very embodiment of the Torah: J. M. Gibbs, “The Son of Man as the Torah Incarnate in Matthew,” in Studia Evangelica, ed. F. L. Cross, 4 (1965), Texte und Untersuchungen, 102 (Berlin: Akademie-Verlag, 1968), 38–46.