At a more fundamental level in a society there hides a concept of reality which is supposed to be beyond question. To express this concept Lesslie Newbigin borrows the sociologist Peter Berger's term 'plausibility structures.' In any society there is a plausibility structure ?things within that are immediately believed; things that contradict it are simply not believed. In other words, every society depends for its existence on patterns of accepted beliefs and practice which determine which beliefs are plausible to members of that society and which are not. These plausibility structures are different in different times and places. Thus, in any society, a belief is held to be reasonable, this is a judgment made on the basis of the accepted plausibility structures (2003:64).

Adding to Berger and Newbigin’s insight, it is possible to assume that multiple plausibility structures may exist within a society. To take a political illustration, there are a right-wing and a left-wing groups within the same people group. In some countries, the difference between the right-wing and the left-wing may be only insignificant ones. But in countries where different political ideologies conflict, the gap between the right and left-wing groups is very wide. The gap is as wide as the difference between Free Democracy and the Communism. One group supports the Free Market Economy while the other fights against it. One group fights anti-Americanism while the other promotes it. Yet, despite the possibility of the existence of multiple plausibility structures, one recognizes that there is still a shared plausibility structure among different groups within a society.

Understanding 'plausibility structures' is important because it is a factor for shaping the way people think. In discussion about the authority of the gospel, the word “reason” is often used as though it were an independent principle of authority to be set alongside revelation and tradition. But, as Newbigin emphasizes, this is a confusion of categories. Reason does not operate in a vacuum. The power of a human mind to think rationally is only developed in a tradition which itself depends upon the experience of previous generations. The definition of what seems reasonable and what does not will be conditioned by the tradition within which the question is being asked (2003:64).

Now, the western plausibility structure is the result of the whole immense shift of thought that took place at the Enlightenment, with all its positive elements. From his cross-cultural perspective Newbigin affirms that every plausibility structure rests upon faith commitments.

Newbigin illustrates how this can be different depending whether the question is asked with Christian and non-Christian tradition. Within an intellectual tradition dominated by the methods of natural sciences, it will appear unreasonable to explain things in terms of the exercise of personal will, of purpose. But if God exists, and if He is capable of revealing His purpose to human beings, then the human reason will be required to understand and respond to the revelation and to relate it to other experience. But it will always do this within a tradition which determines whether or not any belief is plausible, in this case that the tradition of the community which cherishes and lives by the story of the revealing acts of God (2003:64).

On this ground, Newbigin argues that the Christian Church has its own plausibility structure. The gospel offers a radically different vision of how things are from which shapes all human societies. The church, as the bearers of the gospel, therefore inhabits a plausibility structure at variance with those which control all human cultures (2003:64-65).

From his experience of cross-cultural ministry in India for forty years and some years of pastoral ministry experience in England, and from the sociological insights from Peter Berger, Newbigin found that the plausibility structure affects the E-3 evangelism as well as the E-1 and E-2 Evangelism.

First, the difference of plausibility structure is the challenge of foreign mission or cross-cultural evangelism. Western culture has a plausibility structure that is the result of the whole immense shift of thought that took place at the Enlightenment, with all its positive elements. But the difference of plausibility structure within a culture also affects E-1 evangelism or intercultural communication of the gospel message. Just as where Hinduism is a dominant plausibility structure, a Christian statement is not acceptable, a Christian statement is not acceptable in western public life ?it's not acceptable in politics, it's not acceptable in the university essay. Only the manner by which a Christian statement is not acceptable is different. In a Hindu society where Hinduism is a ruling plausibility structure, a Christian statement is not acceptable in favor of a particular religious worldview, that is, Hinduism. In a western society where modernism is a ruling plausibility structure, a Christian statement is not acceptable not because of a particular religious worldview is favored or rejected but because of the dichotomy of facts and value and dichotomy of the public and the private. Religion is simply taken as a private realm of values, while scientific rationalism is accepted as public doctrine.

Second, plausibility structure greatly affects E-1 Evangelism or domestic mission. The modern western society is the kind of society where if one makes statements which are within that plausibility structure, no questions are asked as to what he or she says. But “If one makes, for example, a Christian statement, then that's not acceptable in public life ?it's not acceptable in politics, it's not acceptable in the university essay ?because that represents a particular faith commitment and therefore it is ruled out” (Walker 1988). But what one has to see it that even plausibility structure in modern secular society also rests on faith commitments.” With Newbigin, the mission of the Church in this cultural context is, therefore, to challenge the plausibility structure that dominates the modern western society.