Warning: Liberal warm fuzzies ahead. If you don’t want those, feel free to stop reading now.
The future I am thinking of is accordingly one in which what we now call the different religions will constitute the past history of different emphases and variations within a global religious life. I do not mean that all men everywhere will be overtly religious, any more than they are today. I mean rather that the discoveries now taking place by men of different faiths of central common ground, hitherto largely concealed by the variety of cultural forms in which it was expressed, may eventually render obsolete the sense of belonging to rival ideological communities. Not that all religious men will think alike, or worship in the same way or experience the divine identically. On the contrary, so long as there is a rich variety of human cultures—and let us hope there will always be this-we should expect there to be correspondingly different forms of religious cult, ritual and organization, conceptualized in different theological doctrines. And so long as there is a wide spectrum of human psychological types—and again let us hope that there will always be this—we should expect there to be correspondingly different emphases between, for example, the sense of the divine as just and as merciful, between karma and bhakti; or between worship as formal and communal and worship as free and personal. Thus we may expect the different world faiths to continue as religio-cultural phenomena, though phenomena which are increasingly influencing one another’s development. The relation between them will then perhaps be somewhat like that now obtaining between the different denominations of Christianity in Europe or the United States. That is to say, there will in most countries be a dominant religious tradition, with other traditions present in varying strengths, but with considerable awareness on all hands of what they have in common; with some degree of osmosis of membership through their institutional walls; with a large degree of practical cooperation; and even conceivably with some interchange of ministry.
Beyond this the ultimate unity of faiths will be an eschatological unity in which each is both fulfilled and transcended—fulfilled in so far as it is true, transcended in so far as it is less than the whole truth. And indeed even such fulfilling must be a transcending; for the function of a religion is to bring us to a right relationship with the ultimate divine reality, to awareness of our true nature and our place in the Whole, into the presence of God. In the eternal life there is no longer any place for religions; the pilgrim has no need of a way after he has finally arrived. In St. John’s vision of the heavenly city at the end of our Christian scriptures it is said that there is no temple—no Christian church or chapel, no Jewish synagogue, no Hindu or Buddhist temple, no Muslim mosque, no Sikh Gurdwara. . . . For all these exist in time, as ways through time to eternity.
–John Hick, God and the Universe of Faiths