These are From Leslie Newbigin’s Theology of Mission. They are long to provide a bit of context.
Today the situation is different. The question “What right do you have to preach to us?” is one that is asked with a confidence and vehemence unusual fifty years ago. To this question it is useless to answer by quoting the Great Commission or other texts of Scripture. Why should a Hindu accept the authority of the Christian Scriptures.
From within the Christian church voices are raised to question the whole enterprise of missions, if missions are understood to involve calling people of other faiths to conversion. It is easy to identify these questions.
Why not join with the sincere adherents of all religions in seeking the fullness of the truth to which they all aspire?
Why not join with all people of goodwill in tackling the real human problems of hunger, oppression, sickness, and alienation, instead of seeking more adherents for your religious group?
Is your enterprise not an offense against the unity of mankind? Is not the just unity of all peoples a matter of such urgency that to propagate something so divisive as religion is almost a crime against humanity? …What right have you to engage in a program that is more likely to promote division than unity?
The first step to responding to these questions is to ask the counterquestion that uncovers the hidden assumptions behind the question. What grounds have you for thinking you will come nearer to a solution of the world’s problems by combining the insights of all the religions? What makes you think it is religion that provides the clue to the human needs?
What is your program for the unity of humankind? Around what center and in what organized form do you propose to unite mankind?
The point of countering questions is that they force us to recognize that the questions themselves imply certain commitments about the way in which the whole human situation can be understood and in which we can seek to respond to it. The Christian mission rests upon one such commitment. It is in fact the practical working out of that one commitment. It is futile to try and establish its validity by appealing to some other commitment – that is, by claiming that it ministers to human unity, to development, or to liberation. … The question of authority is not to be answered by trying to demonstrate the usefulness of missions for some purpose that can be accepted apart from the ultimate commitment upon which the missionary enterprise rests.