It is almost two thousand years since the Church received her commission to preach the message of Christ to all nations unto the ends of the earth. In principle we have reached those ends of the earth: the limits of our world have been marked out. Yet what position does the message of Christ occupy in it?
In the ancient cultures of Asia it has never been able to gain a foothold, and in the West where it became one of the historical roots it is still steadily losing in importance and influence. The Christian faith is widely interpreted as one possible form of religious explanation of man's existence, alongside of which others are to be ranged either by an equal right or even as showing greater promise. Religion itself appears to many as only one of many forms of man's understanding of himself, which should be allowed to have its say or which should be combated as harmful.
This is the situation in which the believing Christian finds himself, and he is forced to recognize that the future will only bring this picture into sharper relief,1 that the saying about the little flock will become still more true in spite of all the Church's pastoral and missionary efforts.
The Christian is convinced that in order to achieve salvation man must believe in God, and not merely in God but in Christ; that this faith is not merely a positive commandment from which one could be dispensed under certain conditions; that membership of the one true Church does not constitute a merely extrinsic condition from which it would be appropriate for someone to be freed by the mere fact that he does not and cannot know about it and its necessity.
On the contrary, this faith is in itself necessary and therefore demanded absolutely, not merely as a commandment but as the only possible means, not as a condition alone but as an unavoidable way of access, for man's salvation is nothing less than the fulfillment and definitive coming to maturity of precisely this beginning, for which therefore nothing else can substitute. - In this sense there really is no salvation outside the Church, as the old theological formula has it. But can the Christian believe even for a moment that the overwhelming mass of his brothers, not only those before the appearance of Christ right back to the most distant past (whose horizons are being constantly extended by paleontology) but also those of the present and of the future before us, are unquestionably and in principle excluded from the fulfillment of their lives and condemned to eternal meaningless-ness? He must reject any such suggestion, and his faith is itself in agreement with his doing so. For the scriptures tell him expressly that God wants everyone to be saved (1 Tm 2:4); the covenant of peace which God made with Noah after the flood has never been abrogated: on the contrary, the Son of God himself has sealed it with the incontestable authority of his self-sacrificing love embracing all men.
But when we have to keep in mind both principles together, namely the necessity of Christian faith and the universal salvific will of God's love and omnipotence, we can only reconcile them by saying that somehow all men must be capable of being members of the Church; and this capacity must not be understood merely in the sense of an abstract and purely logical possibility, but as a real and historically concrete one. But this means in its turn that there must be degrees of membership of the Church, not only in ascending order from being baptized, through the acceptance of the fullness of the Christian faith and the recognition of the visible head of the Church, to the living community of the Eucharist, indeed to the realization of holiness, but also in descending order from the explicitness of baptism into a non-official and anonymous Christianity which can and should yet be called Christianity in a meaningful sense, even though it itself cannot and would not describe…