Apostolic Christianity also had its ecumenical problem. This did not, however, consist in more or less harmonious relationships between different kinds of Christian communities which have existed since the first century; according to the New Testament, co-existence was not always peaceful, but it was genuine and profound. The ecumenical problem in the first century concerned the relationship of the Church as a whole with the people of Israel. The fundamental division which New Testament Christian awareness had to face up to was the internal rupture (the hardening of part of Israel) of which the apostle Paul speaks in Romans 11:25; he explains it as a mystery produced in Israel when confronted by the person of Christ, and in particular by his cross and resurrection, a rupture within the people of God which was both painful and dramatic, (I have great sorrow and unceasing anguish in my heart; I could wish that I myself were accursed and cut off from ChristRom. 9:2-3) yet at the same time tremendously fruitful (now if their trespass means riches for the world, and if their failure means riches for the Gentiles, how much more will their full inclusion mean?; and so all Israel will be saved Rom. 11:12,26)

Very early on, the Church lost the awareness of unity between church and synagogue as an essential element in the unity of the People of God. The history of Jewish-Christian relations over the 2,000 years which are behind us is a painful one, with great guilt on the part of Christians, who perhaps have sinned against no one as much as against the Jews.

It will necessitate no small change in contemporary Christian awareness to recognize that Israel, as a community of faith, is an integral part of the ecumenical question. Our churches must become sensitized to the message, disregarded until now, which is found in Romans 9, 10 and 11, that of recovering this lost dimension of their life and witness: the relationship with the Jewish community.