The Expansion of Christianity and the Expansion of Islam: Understanding the Differences

Nineteenth-century Christian missions exploded across the globe with the general expectation that the gospel would penetrate the whole world, and that the evangelism of the world would conceivably be completed within a century or so. That sense of optimism is not so prevalent today, probably in part because of the decline of Christianity in parts of the world that were at one time the fountainhead of Christian faith. A review of the past century reveals that regions in which Christianity had at one time taken root have not always remained Christian for long (think Europe). In contrast, Islam’s progress has tended to be more stable, rarely giving up territory once it has been claimed.

In his book, The Cross-Cultural Process in Christian History (T&T Clark, 2002), Scottish historian Andrew Walls explains the difference between the expansions of the two major religions:

Islam can point to a steady geographical progression from its birthplace and from its earliest years. And over all these years it has hitherto not had many territorial losses to record. Whereas the Jerusalem of the apostles has fallen, the Mecca of the prophet remains inviolate. When it comes to sustaining congregations of the faithful, Christianity does not appear to possess the same resilience as Islam. It decays and withers in its very heartlands, in the areas where it appears to have had the profoundest cultural effects. Crossing cultural boundaries, it then takes root anew on the margins of those areas, and beyond. Islamic expansion is progressive; Christian expansion is serial. (p. 13)

If Walls is correct, this raises some troubling questions. Why does Christianity wax and wane so consistently, while Islam rarely experiences the same fluctuations? Why do the faithful of Christianity possess what seems to be a more tenuous faith?

Walls asks and answers some of his own questions:

Do the resiliency of Islam and the vulnerability of Christianity reflect something of the inherent nature of the two faiths? Does the very freedom of response inherent in the Christian gospel leave it open to ultimate rejection? Is the Christian impact durable only when there is sustained, unceasing penetration of the host culture? Christianity has no culturally fixed element, as is provided by the Qur’an fixed in heaven, closed traditions on earth, perfection in law in shari’a, single shrine in Mecca, and true word every where in Arabic. If the acts of cultural translation by which the Christians of any community make their faith substantial within that community cease—if (if one may use such language) the Word ceases to be made flesh within that community—the Christian group within that community is likely to lose, not just its effectiveness, but its powers of resistance. Most cultures are in frequent change or encounter with others, so the process of translation is endless. (p. 13)

In other words, Islam survives in a given culture because it remains unchanged and sees itself as embattled against cultural difference or change. As a result it can remain monolithic and isolated from the culture. In a world distressed by the culture-destroying power of technology, secularization, urbanization, and other such forces, the unchanging nature of Islam provides a rare sense of security and stability. There is no need to contextualize or adapt. Americans, who have grown up in a constantly changing culture, often forget that not everyone in the world embraces cultural change or the overturning of traditional practices to the same extent that they do.

On the positive side, Christianity has thrived in many parts of the world precisely because the gospel is a message to every tribe and tongue, and while the message must remain the same, the medium and the method are readily adaptable to other cultures.

Walls explains further:

This vulnerability [of Christianity] is also linked with the essentially vernacular nature of the Christian faith, which rests on a massive act of translation, the Word made flesh…Christian faith must go on being translated, must continuously enter into vernacular culture and interact with it, or it withers and fades. Islamic absolutes are fixed in a particular language, and in the conditions of a particular period of human history. The divine Word is the Qur’an, fixed in heaven forever in Arabic, the language of original revelation.

For Christians, however, the divine Word is translatable, infinitely translatable. The very words of Christ himself were transmitted in translated form in the earliest documents we have, a fact surely inseparable from the conviction that in Christ, God’s own self was translated into human form. (p. 29)

A charitable reading of Walls reminds us that the success of Christianity throughout history in so many cultures has been the gospel’s ability to reach people in any culture while maintaining the positive aspects of common grace in that culture. The vernacular nature of the Christian faith presents a temptation and an opportunity. The temptation is to contextualize the message of the gospel, and thereby to lose it. For this, Christians are rightly criticized by Muslims. The diluted gospel of much of evangelicalism and fundamentalism, under the guise of being relevant or old-fashioned, respectively, bears constant witness to this tragedy. The temptation, however, is not necessary, and Christianity can be adapted to various cultures successfully, without compromising the message. Walls concurs:

Christian faith is repeatedly coming into creative interaction with new cultures, with different systems of thought and different patterns of tradition; that (again in contrast to Islam, whose Arabic absolutes provide cultural norms applying throughout the Islamic world) its profoundest expressions are often local and vernacular. It also means that the demographic and geographical centre of gravity of Christianity is subject to periodic shifts. Christians have no abiding city, no permanent sacred sites, no earthly Mecca; their new Jerusalem comes down out of heaven at the last day. (p. 30)

At least two implications arise from these distinctions between Christianity and Islam. First, all of us—not just missionaries—need to translate the faith into the local vernacular in which we find ourselves without compromising the gospel. Christianity is not Islam, and so is not culturally monolithic. Second, rather than seeing the expansion of Christianity as a necessarily universal, progressive missionary certainty, perhaps we ought to realize that the spread of the faith will probably always be influenced by the currents of culture and the degree to which Christians in a particular location remain faithful. The survival of the gospel in a particular area is not assured apart from the faithful preaching and teaching of the Word. This is an especially poignant reality for the church in America where attention and commitment to sound doctrine has fallen precipitously, and, simultaneously, Islam has expanded exponentially. If Islam is hardly ever dislodged once it is established in a region, the only hope for the spread of Christianity is the wholesale commitment of the church to the centrality of the gospel.

Mark Farnham is Assistant Professor of Theology and New Testament at Calvary Baptist Theological Seminary (Lansdale, PA). He and his wife, Adrienne, grew up in Connecticut and were married after graduating from Maranatha Baptist Bible College (Watertown, WI). They have two daughters and a son, all teenagers. Mark served as director of youth ministries at Positive Action for Christ (Rocky Mount, NC) after seminary and pastored for seven years in New London, Connecticut. He holds an MDiv from Calvary and a ThM in New Testament from Gordon-Conwell Theological Seminary (South Hamilton, MA). He has also studied ancient manuscripts at Harvard Divinity School and philosophy at Villanova University. He is presently a doctoral student at Westminster Theological Seminary (Glenside, PA) in the field of Apologetics. These views do not necessarily reflect those of Calvary Baptist Theological Seminary or its faculty and administration.