Introduction: The Mission That Is Not Finished

On a Sunday morning, one person may wake within walking distance of several churches. He can choose among congregations that differ in denomination, worship style, theological emphasis, size, age, language, and social atmosphere. Printed Bibles are inexpensive. Several modern translations are available in his mother tongue. Sermons, courses, podcasts, commentaries, apologetic resources, and entire seminary lecture series can be accessed from a phone before breakfast. Christian friends may already be present at school, university, or work. Even if he has never entered a church, Christian ideas have probably reached him through history, public holidays, media, family memory, political debate, music, or literature.

None of this guarantees Christian faith. It does not guarantee accurate knowledge of Christianity. The churches nearby may be weak, unhealthy, divided, or distrusted. The person may have heard only caricatures of Christian belief. He may reject Christianity after serious consideration or barely think about religion at all. Yet one fact remains: Christianity is comparatively easy for him to investigate. If he wants to understand what Christians believe, meet practicing Christians, attend worship, or read Scripture, there are realistic pathways available to him.

Another person inhabits the same global Christianity under radically different conditions.

She may live in a country where Christian material is technically accessible online. A Bible may exist in a national language she can read, though not necessarily in the language she speaks most naturally at home. A Christian minority may live elsewhere in the country. Satellite television, social media, or private messaging may make Christian information reachable. She might even have heard the name of Jesus many times.

Yet no close friend follows Christ. The nearest visible church may belong to another ethnic community, another caste, another language, or a social group her family does not enter. Visiting could create suspicion. A public change of religion might threaten marriage prospects, inheritance, employment, family belonging, or physical safety. If she becomes interested in Christianity, the crucial question may not be whether a website loads. It may be whether there is a trustworthy human being with whom she can speak without exposing herself to consequences she is not prepared to bear.

Both people live in a world in which Christianity has become one of humanity’s most geographically widespread religions. They do not possess the same access to it.

The inequality between those two worlds is the subject of this book.

A Global Religion With Unequal Reach

Christianity began as a small movement within first-century Judaism in a peripheral province of the Roman Empire. Within centuries Christian communities existed across the Mediterranean, North Africa, Armenia, Persia, India, Central Asia, and eventually China. Christian faith took form in Greek, Latin, Syriac, Coptic, Armenian, Ge’ez, and many other linguistic worlds. Long before modern European empire, Christians were already crossing cultural boundaries, translating texts, forming churches, disputing theology, migrating, and adapting Christian life to different civilizations.

Modern missionary movements later extended this geography dramatically. Catholic orders, Protestant societies, independent missions, indigenous evangelists, Bible translators, teachers, physicians, merchants, migrants, and local church networks carried Christian witness into new places and social worlds. Translation projects rendered Scripture into thousands of languages. Churches formed where Christianity had previously been marginal or absent. Schools, hospitals, seminaries, publishing networks, and missionary organizations became important institutions in many societies.

The record is morally mixed. Missionaries sometimes opposed exploitation; sometimes they benefited from it. Some defended local peoples against colonial power; others carried racial assumptions, paternalism, or forms of cultural coercion. Indigenous Christians often spread Christianity far beyond the direct reach of foreign missionaries, even while older mission histories centered foreign personalities and institutions. The result was never a simple story of one civilization transmitting a finished religion to passive recipients.¹

The twentieth century transformed the map again. Sub-Saharan Africa became one of world Christianity’s major demographic centers. Latin American evangelical and Pentecostal movements expanded. South Korea became a substantial missionary sender. African-led churches appeared in European cities. Latin American missionaries served in Africa, Asia, Europe, and the Middle East. Filipino Christians carried their faith through global labor and migration networks. Churches once described principally as mission fields increasingly became missionary actors themselves.

The familiar map—the Christian West sending to the non-Christian “rest”—can no longer describe the church accurately. It was always historically incomplete. It is now empirically untenable.

Christianity is genuinely global.²

Mission is increasingly multidirectional.³

And still the mission is unfinished.

What Does “Unfinished” Mean?

That sentence can sound obvious until one asks what exactly remains incomplete.

One answer has dominated much modern evangelical mission strategy: unreached people groups. The category has performed a valuable service. National averages conceal internal diversity. A country may contain millions of Christians while particular ethnic, linguistic, caste, or religious communities possess almost no locally rooted Christian presence. People-group research forces churches to notice populations that might otherwise disappear inside political borders.

But unreached is not a biblical label visibly attached to particular communities. It is a modern missionary classification. Different organizations disagree about how many people groups exist, whether the same people should be counted separately in each country, which Christian traditions should be included in particular thresholds, and what level of Christian presence should count as sufficient for a population to sustain wider witness. These disagreements do not make mission research useless. They make definitions indispensable.

The same caution applies to some of the most powerful missionary slogans. Claims that billions of people have “never heard the gospel,” that a fixed percentage of missionaries serves “the reached,” or that almost none of Christian giving reaches the unreached are rhetorically potent. They are also often stronger than the data behind them. A serious Christian case for mission does not need exaggeration. The real disparities are large enough.

This book therefore asks a harder question than whether a population appears below one percentage threshold:

Who possesses realistic access to intelligible Christian witness, Scripture, Christian relationships, discipleship, and locally rooted Christian community—and who does not?

That question immediately shows why access is not one thing.

A Bible can exist without being understandable in the language through which a community lives most deeply. Christian media can be available while trustworthy Christian relationships are absent. A church building can stand nearby while remaining socially inaccessible because of caste, ethnicity, class, language, or historical hostility. A missionary can be present while the emerging church remains unable to continue without outside leadership or money. A country can have a long Christian history while younger generations find Christianity socially implausible or institutionally untrustworthy.

The unfinished mission is therefore not one empty region on a map. It is a pattern of unequal access.

Access Does Not Mean Response

This distinction is essential because missionary urgency can otherwise become manipulative. Christian mission aims at response: repentance, faith, baptism, discipleship, participation in Christian community. Yet Christians do not control response. The gospel may be clearly communicated and sincerely rejected. A society may possess abundant churches and Bibles while Christian affiliation declines. A person may know faithful Christians, understand their beliefs, and remain unconvinced.

That is not the same missionary problem as having almost no realistic opportunity to encounter Christian witness at all.

The difference matters strategically and morally. If a population has high informational, linguistic, relational, and ecclesial access but low Christian response, the church may need better apologetics, renewed credibility, patient evangelism, church reform, or intergenerational discipleship. If a population lacks Scripture in a usable language, has almost no Christian relationships, and faces heavy social penalties for religious exploration, the need is different. Both situations matter. They should not be collapsed into one word.

This book will therefore not use unreached as a synonym for every place where few people are evangelical Christians. Nor will it call a society “reached” as though its members no longer matter once a statistical threshold has been crossed. Missionary categories are strategic tools, not declarations about the value of populations or the completion of Christian responsibility.

People Before Categories

The methodological problem has a moral dimension.

Statistics are useful precisely because human beings are easy to overlook at scale. A global map can show where Christian presence is thin. A language database can reveal communities without translated Scripture. Migration data can show how populations are moving. Religious surveys can challenge stereotypes. Mission research can direct attention toward places that established Christian institutions would otherwise ignore.

Yet categories can begin to replace persons.

A Muslim community becomes a percentage. A minority language becomes a translation status. A refugee becomes a diaspora opportunity. An ethnic population becomes a code in a missionary database. A person becomes “a target.”

Christian theology should resist this reduction more strongly than anyone. Human beings are not strategic objects. They are creatures made in the image of God, embedded in families, histories, languages, memories, loves, obligations, and communities. They work, marry, grieve, celebrate, doubt, worship, fear, hope, and make decisions under social pressures that no map can fully capture.

Mission statistics should therefore increase the church’s attention to human reality rather than flatten it.

The book will use demographic estimates, people-group classifications, religious surveys, institutional reports, and missionary research extensively. Every number remains subordinate to the people it describes.

Neither Triumph Nor Indictment

Mission history creates another temptation. One version tells a story of heroic missionaries who carried Christianity around the world through sacrifice and courage. Another interprets mission principally through colonial domination and cultural destruction.

Neither can explain the evidence.

Missionaries translated Scripture, formed churches, founded schools and hospitals, opposed some forms of exploitation, learned difficult languages, challenged destructive practices, and crossed extraordinary cultural boundaries. Many served in obscurity rather than glory. Women constituted a major share of Protestant missionary work even when formal histories and institutions often minimized their authority. Local evangelists and catechists carried Christian faith through networks foreigners could not reach. Indigenous church leaders turned a received faith into a locally transmitted one.

Missionary institutions also became entangled with empire, racial hierarchy, paternalism, coercive power, donor control, foreign cultural assumptions, and spiritual abuse. Some missionaries interpreted their civilization as evidence of Christian superiority. Others were unable to see how their passports, wealth, or institutions changed the meaning of their presence. Churches could become dependent on outside structures created in the name of service. Christian authority could be used to suppress legitimate disagreement.

Sometimes both realities existed in the same institution.

Honest missionary theology therefore needs enough confidence to celebrate faithfulness and enough self-criticism to name failure. The Christian doctrine of sin should make this combination unsurprising. No nationality possesses immunity from the temptations associated with money, authority, culture, and institutional self-preservation. Replacing Western missionaries with Korean, African, Latin American, or other missionaries does not automatically remove the problems created by unequal power.

A global church can reproduce old missionary hierarchies with new actors.

Why Do the Gaps Persist?

If Christianity is global, why does meaningful Christian access remain so unequal?

One obvious answer is insufficient missionary deployment. In many contexts, more workers are genuinely needed. Yet this answer is only part of the explanation.

Missionary resources do not distribute themselves through a rational global system. Churches support people they know. Agencies remain where they possess relationships, property, language expertise, schools, and legal structures. Donors prefer outcomes they can see. Pioneer work may require years of language learning before any visible church exists. Some governments restrict foreign religious work. Some communities impose severe social consequences on converts. Some languages demand long preparation. Trust grows slowly. Churches naturally attend to urgent needs nearby. Christians disagree about what sort of missionary call is necessary. Workers sometimes leave before local leadership can mature. Foreign money and institutional authority can keep outsiders central long after local Christians should be exercising greater control.

The remaining inequalities persist for more than one reason: resources, political and social barriers, cultural distance, institutional structures, missionary vocation, time, and power all matter.

The complexity does not reduce urgency. It tells us what sort of mission might actually address the problem.

A Christian Standpoint

This book is written from within historic evangelical Christianity.

It assumes the authority of Scripture, the centrality and uniqueness of Christ, his death and resurrection, salvation by grace through faith, the necessity of repentance and faith, the importance of the church, Christ’s command to make disciples among the nations, and his return. Evangelism, conversion, discipleship, Scripture, church formation, and theological maturity therefore remain central to mission as this book uses the term.

That standpoint is not disguised as religious neutrality.

It also imposes an obligation to represent other religious communities truthfully. Muslims will not be described as one monolithic world. Hindu traditions will not be reduced to one systematic theology. Formal Buddhist affiliation will be distinguished from lived religious practice. Religiously unaffiliated people will not automatically be called atheists. Catholic, Orthodox, Oriental Orthodox, Anglican, Protestant, Pentecostal, and independent Christian communities will not be collapsed into one undifferentiated population where their distinctions matter.

The fact that this book is evangelical also means that some mission databases it uses reflect evangelical strategic concerns. A low evangelical percentage says something specific about evangelical presence. It does not mean that Catholic, Orthodox, or other Christian communities are absent, invalid, or irrelevant. That distinction will become especially important when we examine the Middle East, Eastern Europe, Africa, and India.

Truthfulness belongs to Christian witness.

Five Questions

The argument proceeds through five questions.

Part I asks what Christian mission actually is. Before counting progress, we need to understand God’s purpose toward the nations, Christ’s commission, the missionary movement of Acts, and what Scripture permits Christians to mean when they speak of finishing mission.

Part II asks how Christianity became global. It follows Christianity across early African and Asian worlds, through the complicated age of empire and modern mission, into the demographic transformation that made the contemporary church increasingly polycentric.

Part III asks where meaningful gospel access remains weak. It examines people-group classification, Muslim-majority contexts, South Asia, lived religion, secularization, language, Scripture, cities, and migration. The investigation will eventually return to the question of what kind of locally rooted Christian communities can sustain witness after outside missionary activity recedes.

Part IV asks why the gaps persist. It examines allocation, restriction, cultural distance, institutional gravity, missionary calling, short horizons, and distorted power.

Part V asks what faithful mission therefore requires. It moves from access toward local churches, contextualization, local ownership, global partnership, missionary formation, new legitimate pathways, and participation by the whole church.

Only after those questions have been answered can we return responsibly to the title.

Urgency Without Panic

The missionary need is real.

Human lives are brief. Languages change. Churches decline. Political opportunities open and close. Generations grow up. Migration rearranges communities. Christian obedience should not become an indefinitely postponed aspiration.

But urgency does not require panic.

The church does not control the timetable of Christ’s return. No mission agency possesses a secret formula for completing history. Statistics need not be inflated. Missionaries need not be idealized. Churches do not need to manufacture guilt in order to send faithful workers.

Christian mission can be urgent because Christ commands obedience and patient because discipleship, language, trust, and churches take time.

Nearly two thousand years after the earliest Christian witnesses began moving outward from Jerusalem, Christianity has never been more geographically widespread. Information has never traveled more easily. The church has never possessed so many potential sending centers.

Yet access remains profoundly unequal.

Why?

And what would faithful Christian mission require now?

We begin where mission itself begins: with the God who sends.

Footnotes

1. Dana L. Robert, Christian Mission: How Christianity Became a World Religion (Wiley-Blackwell, 2009); Andrew F. Walls, The Missionary Movement in Christian History: Studies in the Transmission of Faith (Orbis Books, 1996); Lamin Sanneh, Translating the Message: The Missionary Impact on Culture, 2nd ed. (Orbis Books, 2009). ↩

2. Pew Research Center, How the Global Religious Landscape Changed From 2010 to 2020 (June 9, 2025). The report estimates 2.3 billion Christians in 2020, or 28.8 percent of the global population, from more than 2,700 censuses, surveys, registers, and related sources. ↩

3. Jehu J. Hanciles, Migration and the Making of Global Christianity (Eerdmans, 2021); Samuel Escobar, The New Global Mission: The Gospel from Everywhere to Everyone (InterVarsity Press, 2003). ↩