Pope John Paul II above all has contributed decisively towards achieving the breakthrough with this declaration, which can only be defined as historic, as well as to expanding and intensifying it. He has often repeated the term of the “unabrogated covenant” and made it the foundation of the redefinition of the relationship between the Catholic Church and Judaism.[28] Thus “Nostra Aetate” opened a new chapter in the predominantly dark history of the relationship between Jews and Christians. It represents a new beginning which has in the meantime found broad resonance in many declarations and official statements at Bishops’ Conferences, Synods and Ecclesial Commissions.[29] In the meantime the term “unabrogated covenant” has become the starting point and foundation of a renewed theology of Judaism within both Catholic and Protestant theology.[30]  In place of the treatises “Contra Judaeis” we now find treatises “De Judaeis” or “Pro Judaeis”. For more recent theology Judaism is not only sociologically but also theologically a current entity.  God’s covenant with Israel has not been overtaken and replaced by the new covenant. God has not abrogated his covenant with this people; he has not rejected or forgotten his people. God is still inclined towards these his people in love and faithfulness, in mercy, judgement and forgiveness; he is with them and among them in the difficult hours and times of their history above all. As a member of his people, each Jew continues to stand beneath the promise.

5. One covenant or two covenants?

“Nostra Aetate” was a necessary and a good new beginning, and the Catholic Church can never retreat back to the previous position. “Nostra Aetate” was of course only the beginning of a new beginning. We are only at the start of a new start of a “Christian Theology of Judaism”; despite many good initiatives such a theology of Judaism still remains a desideratum. Many decisive questions still remain open. 

Many recent approaches overlook the fact that both Judaism and Christianity cannot simply be equated with their biblical forms. Post-biblical rabbinical Judaism was formed only after the destruction of the temple in 70 AD by differentiating itself from aspiring Christianity and excluding the Christians from the synagogue. On the other hand, Christianity also had to differentiate itself from Judaism. In the form in which they exist today, both are post-biblical entities.[31] The Pauline statements, which are at home in a different historical context, cannot be directly applied to their reciprocal relationship, that is, not without the necessary intermediate hermeneutical considerations. In addition, the biblical testimony is multi-layered and proves resistant to a systematic standardisation. The term “unabrogated covenant”, which has been so important in the new initiatives, should therefore not be regarded in isolation; it does not cover the whole multi-layered New Testament covenant theology. We are still far removed from a synthesis and even more from a consensus.

The central question which Jewish-Christian dialogue revolves around for us is: How can the thesis of the continuing covenant be reconciled with the uniqueness and universality of Christ Jesus, which are constitutive for the Christian understanding of the new covenant? Can or should we replace the exclusivism of the substitution theory with a dualism in the sense of a co-existence of the old and new covenants, or even a pluralism in the sense of a number of covenants? Giving up the claim to the universal truth and salvation of Christ Jesus would be equivalent to giving up Christianity itself.[32] So in this question Christology remains the real stumbling block.

In attempting to answer this question two theories have been developed during the past decades: the One Covenant Theory and the Two Covenant Theory.[33] The question is: Is there only one covenant which encompasses both Jews and Christians? Or should we speak of two covenants which exist in an alternative, a correlative or a dialectical relationship to one another? Both theories are represented by both Catholic and Protestant theologians with many modifications, transitions and intermediate positions.

The One Covenant Theory correctly maintains the unity of God’s plan of salvation, but it presumes a unified canonical biblical covenant concept which does not exist in this form. It stands in danger of either claiming Judaism for Christianity or making Christianity into a sort of reformed Judaism, thus obscuring either the particularity of Judaism or the uniqueness and universality of Christ Jesus. The Two Covenant Theory avoids these dangers. Its strength is that it can maintain the relative autonomy of Judaism and Christianity. Even if it wishes to maintain the interconnectedness of Judaism and Christianity, this is not totally successful; it runs the risk of considering the two as totally independent entities. It must therefore on the one hand play down the Jewish roots of the church while on the other hand failing to do justice to the universal Christological claim.

The relationship of Judaism and Christianity is thus so complex both historically and theologically that it cannot be reduced to one of the two theories or to a formula which is valid for all time.[34]  Many more recent versions get no further than an indecisive “both – and”.[35] Progress can only be made in this situation if one takes into account the hermeneutical and theological presuppositions of the entire discussion.

Since Judaism and Christianity have followed different paths we can no longer make direct connections with Paul. Judaism and Christianity have developed two different interpretations which one cannot judge from a neutral standpoint if one considers them as a theologian and not as a religious studies scholar. Both are derived from a faith decision. At the heart of the Christian faith is the affirmation of Jesus as the Christ in whom all the promises of the old covenant have become Yea and Amen (cf. 2Cor 1:20). Therefore it is the fundamental hermeneutical presupposition of Christian theology to read the promises of the old covenant in the light of their Christological fulfilment. It establishes a connection with the old covenant while at the same time contradicting the Jewish claim to the same covenant promises.[36] That does not lead back to the substitution theory, unless the Christological interpretation is inadvertently turned into an ecclesiological interpretation, that is, if the balance of promise from the Old Testament is taken seriously and the eschatological difference between the fulfilment which has already been accomplished in Christ Jesus and the still anticipated consummation is held open. This difference leaves room for the “still” of the continuing validity of the covenant with Israel, and allows us to take up Romans 11 anew so that we can approach an answer to the question which occupies us here.

6. Historical concurrence on the basis of eschatological hope

The answer which Romans 11 gives us is not a theory, but rather an image. Images are also better suited to expressing the dialectic of continuity and discontinuity, of connection and contradiction – which can scarcely be held in balance conceptually – and to bringing the dialectic to a standstill as it were.[37] Images also have the advantage of being open to interpretation and not prescribing how they are to be understood in the same way that concepts do. Images can therefore legitimately be applied interpretatively to different situations.

In the Epistle to the Romans Paul uses the image of the root of the olive tree for Israel into which the church of the Gentiles is grafted like a branch. The root bears the branches and gives them sustenance (cf. Rom 11:16-24). With this image Paul resists any Christian triumphalism. “It is not you that support the root, but the root that supports you” (11:18). The church is forever dependent on Israel, it cannot turn away from or against Israel without cutting itself off from its roots, thus damaging and weakening itself. If it does so all the same, it denies and harms itself. “For salvation is from the Jews” (Jn 4:22).

According to Franz Rosenzweig the Christian needs the Jew standing behind him.[38] Holding fast to the Old Testament during the formation of the canon preserved Christianity from sliding into Gnosticism and sharpened its awareness that it was anchored in history and in the physicality of the salvation story.[39] “Caro cardo salutis” (Tertullian). Traditional theological anti-Judaism has cut the church off from its bearing and sustaining root, and has led to its impoverishment and weakening. This was one of the causes for the fact that most Christians did not oppose the crime of the Shoah with the resistance which one could have expected from them. 

But Franz Rosenzweig also knows the reverse danger posed by Judaism cutting itself off in its self-sufficiency and closing the door to dialogue.[40] For Judaism cannot simply be indifferent to the branch of Christianity which was grafted into the Jewish rootstock and has in the meantime grown into a great tree, without denying a part of itself. For the promise given to Abraham that all the nations are blessed in him (cf. Gen 12:3 etc) has made its way toward fulfilment by way of Christianity.[41]

On this pathway fundamental faith constructs of Judaism have been universalised, and Jewish monotheism, the Ten Commandments, and its messianic hope have been exported to the world. In more recent times that has often occurred in a secularised form leading to the contemporary utopias and the modern belief in progress; the resulting consequences are the cause of the crises destabilising the modern world. Jews and Christians therefore share a common responsibility for the future of the world. Both together are called to work towards an order of peace with justice.[42]

Thus Jews and Christians are different but dependent upon one another for the sake of their individual identity. They are like two brothers who have the same father in heaven and in Abraham the same father in faith. They can become alienated and hostile brothers, and unfortunately that has often been the case. But they can also acknowledge and find one another again as Joseph found his brothers again after a long history of guilt and betrayal (cf. Gen 45). A similar process of rediscovery and reunion is in its initial stages in Jewish-Christian dialogue. This is not possible without repentance and rethinking.

In the end the relationship of Israel and the church is a mystery of election and judgement, of guilt and even greater grace, which Paul is able to approach only with doxology (cf. Rom 11:33-36). The continuing existence of Israel confronts us inevitably with God’s unconditional faithfulness to his people. The existence of the church is also a mystery, for without deserving it, out of pure grace, God’s covenant commitment has been extended to the Gentiles. So the relationship of Israel and the church is an absolute mystery.

A mystery is not an irrational entity which we are forbidden to think about, instead it is true that: “Fides quaerens intellectum” (Augustine, Anselm of Canterbury). Paul himself in Romans 11 indicates the direction of such an understanding; not a theory but a docta spes, an account of the hope (cf. 1Pet 3:15 f) which is certain that in the end Israel and the church will be reunited (cf. Rom 11:26.32).

The rationality of this hope is found in both the Jewish and the Christian tradition. It is the shared conviction that God will in the end reveal his divinity and and establish his kingdom. According to Jewish belief the Torah was created before the world and the world was created according to the measure of the Torah.[43] This universal destiny of the historically particular Torah finds expression in the promise of the gathering of all peoples at the end of time and of Jahweh’s eschatological rule over all peoples. According to this hope at the end of days Jews and Gentiles will stand shoulder to shoulder and await the Messiah. “On that day the Lord will be one and his name one” (Zech 14:9).[44]

In the New Testament Christ Jesus has taken the place of the Torah.[45] All creation has been directed toward him and in him everything finds its fulfilment (cf. Jn 1:3-4.10; Col 1:16 f). In the church consisting of Jews and Gentiles (cf. Eph 2:11-22) the eschatological gathering of the peoples has already begun (cf. Is 2:2-5; Mic 4:1-5; Mt 8:11; Lk 13:29), but the promise made to Abraham has not yet been fulfilled completely. The remaining balance of the promise will only be fulfilled when in the end Israel too is saved (cf. Rom 11:2.32) and “God may be all in all” (1Cor 15:28).

Jews and Christians share a common root with one another and a common hope for one another. Regardless of the Christological difference they are, in the current eschatological interim, two concurrent parts of God’s one people on the basis of guilt and even greater grace, co-existing as rivals in the positive as well as in the conflict-ridden sense of the word. They have to follow the path of history beside one another. Co-existence can turn into bloody conflict and aggressive contradiction, but it can also become mutually enriching complementarity and mutually assisting cooperation. Both are possible and both have occurred within history. But fundamentally neither Christians nor Jews (cf. Rom 11:18) can achieve consummation (cf. Heb 11:40) without one another.

Therefore, following the catastrophe of the Shoah, Jews and Christians should – without giving up their differences – overcome the alienation and animosity which derives from their differentness, and seek to realise their shared hope in anticipation already within history. They should stand “shoulder to shoulder” with one another and be there for one another, committing themselves to justice (zedaka) and peace (shalom) for the good of all. Thus they can be a blessing to one another and the world.

I cannot summarise this thought better than with the words of Martin Buber:

There is a way of walking together without coming together. There is a way of working together without living together. There is a way of unifying the prayers without unifying those who are praying. … Intentions which will meet at their goal have their nameless alliance in their orientation, differentiated on the basis of their truths but shared on the basis of the reality of fulfilment. We must not pre-empt, but we should prepare the way.[46]