Islam That Gently Took Root, Churches That Remained Static: Indonesian Islam and the Trajectories of Christian Mission

Young-ung Park (Member of the Acean Studies Association), Cheol-young Lee (Head of the International Affairs Research Association), Ji-eun Lee (Editorial Board)

Indonesia, home to the world’s largest Muslim population and an expansive plural society encompassing hundreds of islands and cultures, offers a crucial setting for examining how religion and culture shape social life. In this context, Islam did not spread through warfare or coercion, as occurred in various other regions. Instead, it gradually took root through commerce, cultural exchange, and interpersonal networks. The form of Islam introduced by Sufi merchants engaged local cultures gently, and over time, contemporary Indonesian Islam came to embody notable diversity and inclusiveness.

Figure 1 Istiqlal Mosque in Jakarta Note. Photograph by Muhammad Syahrul Munir, reproduced from Google Maps Photos https://maps.app.goo.gl/tyx1nYdYU4JPp5BK6

Yet this image of moderation does not capture the entirety of Indonesia’s religious landscape. Although public narratives emphasize religious freedom and tolerance, significant but often unseen tensions persist between majority and minority religious groups. Within a social structure in which Muslims constitute the majority, minority religions—including Christianity—remain constrained by systems of discrimination, surveillance, and restriction. Examining this landscape naturally raises several questions: How did Islam permeate Indonesia in such a gradual, relational manner? What makes Indonesian Islam distinctive? And within this complex structure, how do Christian communities sustain their faith and discern appropriate modes of gospel proclamation? These questions extend beyond Indonesia itself. They speak to the broader challenge faced by all who live amid the realities of religious diversity and interreligious tension while sharing daily life with neighbors in need of the gospel.

How Did Islam Enter Indonesia?

Islamization in Indonesia occurred gradually and remarkably peacefully—an uncommon pattern in the global history of religions. Whereas Islam elsewhere often expanded through military or political conquest, its spread in Indonesia followed a different trajectory. From the seventh century onward, Muslim merchants from Arabia, Persia, and India traversed the Indian Ocean and the Strait of Malacca, gradually introducing Islam to the archipelago. These merchants were not merely transient visitors; many settled permanently over successive generations, forming dense networks of kinship and trust with local populations. Because trust was essential to maritime trade, merchants emphasized honesty, integrity, and moral discipline. Local communities interpreted these virtues as expressions of religious sincerity, and Islamic ethics thus entered society intertwined with commercial reliability. Intermarriage between Muslim traders and local women further facilitated the spread of Islamic practice. Through these kinship-based networks, religious and everyday life increasingly converged (Ricklefs, 1993).

The fact that many early transmitters of Islam were affiliated with Sufi traditions also contributed significantly to the unique form that Islam assumed in Indonesia. Sufism emphasizes inner spirituality, personal encounters with the divine, and the communication of religious sensibilities through stories and symbols rather than strict legalism. This orientation resonated naturally with Indonesia’s religious environment, long shaped by Hinduism, Buddhism, and indigenous animisms. Sufi teachers did not confront or attempt to displace existing practices but instead articulated Islamic concepts within symbolic frameworks already familiar to local communities. Consequently, Islam was not regarded as a foreign system antagonistic to local traditions but as a spiritual framework capable of coexistence and integration (Azra, 2004).

A central group that facilitated early Islamization was the Wali Songo, the nine Islamic scholars and teachers active between the late fourteenth and early sixteenth centuries. Among them, Sunan Kalijaga is the most renowned. He fostered the cultural reception of Islam by adapting Wayang, the traditional shadow puppet theater rooted in Hindu epics, to incorporate Islamic figures and narratives. Other members likewise disseminated Islamic teachings through traditional music and artistic forms and established Islamic boarding schools, laying the groundwork for the subsequent rise of Islamic sultanates. Through artistic mediation, Islam became embedded as a culturally integrated rather than foreign religious experience (Geertz, 1960).

From the thirteenth century onward, regional kingdoms increasingly adopted Islam as a governing ideology, shifting its expansion from individual acceptance to state-level integration. The Sultanates of Pasai in Sumatra and Malacca embraced Islam to enhance political legitimacy and commercial influence, and after the decline of the Majapahit Kingdom, new Islamic sultanates emerged in Java. Once rulers adopted Islam, their subjects largely followed. The intertwining of religious identity and political authority allowed Islam to function as a cohesive force across the archipelago while preserving regional cultural variations (Pires, 1990).

In short, Islamization in Indonesia was not a process of conquest or coercion but one of relational, culturally embedded, and politically mediated growth. Islam did not invade Indonesia; it lived alongside its people and gradually took root. This trajectory underlies the moderation, diversity, and cultural hybridity characteristic of Indonesian Islam today—arguably one of the most indigenized forms of Islam in the world.

What Are the Characteristics of Indonesian Islam?

Indonesian Islam is not monolithic but rather a hybrid, multilayered, and plural religious formation shaped across centuries of cultural and political interaction. Because Islam spread without significant coercion, its development tended to accommodate local customs and symbolic systems rather than impose the strict norms of any particular Islamic lineage. Java, Sumatra, Sulawesi, and Borneo each possessed distinct religious histories, and Islam grew by integrating these regional traditions. As a result, Indonesian Islam came to embody what is often termed Islam Nusantara, an expression of Islam that embraces local cultural forms rather than replicating Arab or South Asian patterns (Azra, 2004). Notably, Nusantara—literally “the islands of the great seas”—is a traditional term for the Indonesian archipelago.

The Javanese expression of Islam illustrates this character most clearly. Javanese religiosity historically combined ancestor veneration, spirit beliefs, and Hindu-Buddhist cosmologies. Islam did not seek to repudiate or displace these traditions; instead, it accommodated and blended with them. This produced the syncretic spirituality known as Kejawèn, which prioritizes inner harmony over formal ritual observance and values communal peace and spiritual balance above strict adherence to sharia. Although such expressions may appear heterodox to outsiders, Javanese communities regard them as essential to maintaining cultural equilibrium (Geertz, 1960).

Figure 2 Islamic education at the Jakarta Islamic Center Note. Photograph by Farhah Ryha, reproduced from Google Maps Photos https://maps.app.goo.gl/oMSCt9Wf4HE2HMjc8

Tolerance toward religious diversity constitutes another defining feature of Indonesian Islam. Indonesia’s national ideology, Pancasila, whose first principle is “Belief in the One and Only God,” affirms religious plurality while simultaneously requiring recognized religions to possess a monotheistic framework. While this appears to guarantee religious freedom, it also exerts institutional pressure on religious communities to reconfigure their doctrines accordingly. For instance, Hinduism—traditionally polytheistic—rearticulated its theology by identifying Brahman as a supreme deity (Beatty, 1999). This arrangement allows Indonesian Islam to maintain an official image of tolerance while preserving its social dominance as the majority religion.

Indonesian Islam also places strong emphasis on moderation and social harmony. Nahdlatul Ulama (NU), the largest Islamic organization in the country, represents a tolerant expression of Islam rooted in traditional Sufism and has long served as a buffer against radical Islamist currents. NU’s conception of Islam Nusantara stresses cultural coexistence and social concord rather than violent jihad. This orientation aligns with Indonesia’s self-representation in the international arena as a model of “moderate Islam” (Fealy & White, 2008). Such traditions have allowed Indonesia—despite its immense Muslim population—to develop mechanisms that mitigate the spread of radicalism.

At the same time, Islam’s status as the majority religion generates tensions for minority communities. In certain regions, Islamic identity becomes a tool of political mobilization, fueling social and religious conflict. Thus, Indonesian Islam embodies a dual structure: it exhibits tolerance and flexibility, yet also harbors exclusivist tendencies and localized tensions. It is neither simply moderate nor merely conservative, but a multilayered religious ecosystem shaped through the interaction of regional, cultural, political, and economic factors.

How, Then, Should Mission Be Carried Out in This Context?

Any discussion of mission in Indonesia must begin with the recognition that a substantial number of churches already exist throughout the country. Large congregations flourish in major cities, and numerous denominations have established themselves across diverse regions. With approximately 29 million Christians—about 10% of the population—Indonesia already possesses a sufficient foundation for indigenous church growth and mission development. Nevertheless, many churches direct most of their attention inward toward caring for their own communities and exhibit caution in expressing the gospel publicly within a Muslim-majority society.

Indonesia’s Christianization rate has shown only minimal fluctuation: 8.9% in 2000, 9.9% in 2010, and 10.3% in 2020, remaining relatively stable overall (Badan Pusat Statistik, n.d.; Kementerian Agama Republik Indonesia, n.d.). These slight changes are often attributed to varying birth rates in eastern regions—where Christianity is more prevalent—and, according to some analyses, to methodological differences among census instruments (Pew Research Center, 2025).

This stagnation results partly from pressures emerging from legal and social environments, but more importantly from the perception that evangelistic activity threatens community safety. As a result, many churches share the conviction that “evangelism is dangerous” and that preventing social conflict must take precedence. They thus adopt the posture of faith communities focused primarily on internal spiritual life while remaining hesitant or passive in collective gospel witness. Consequently, evangelism is frequently relegated to the private life of individual believers rather than embraced as a communal calling.

Figure 3 Worship service at Life Messenger Community Church Note. Image reproduced from Instagram account @mylmcc.id https://www.instagram.com/mylmcc.id/

Mission in Indonesia, therefore, must involve more than the deployment of external missionaries. It requires awakening and mobilizing existing churches to engage in evangelism within their own context—an internally generated evangelistic movement. Moreover, Indonesia’s geographic and cultural position equips its churches to reach neighboring Muslim-majority societies such as Malaysia, Brunei, and Singapore. If spiritually renewed, Indonesian churches have the potential to serve as a regional hub for mission in Southeast Asia. Churches in nearby Christian-majority nations, including the Philippines, should partner with Indonesian churches to help them move beyond a worship- and program-centered model of faith and recover the identity of evangelizing and sending congregations. Ultimately, the heart of mission in Indonesia is not sending additional missionaries but enabling the millions of Christians already present to reclaim their missionary identity.

Recovering this identity does not depend primarily on sophisticated programs or abundant economic, theological, or institutional resources. Western and Korean churches have long possessed such resources yet still experienced decline. To rekindle a missional identity and maintain the integrity of the gospel, it is essential to rely on Scripture and the work of the Holy Spirit. Within the pluralistic religious environment shaped by Pancasila, Indonesian churches need renewed passion for the foundational convictions of “Scripture alone” and “Spirit alone.”

Furthermore, mission among Indonesian Muslims cannot proceed from religious superiority or depend solely on economic, educational, or intellectual assistance. The strong religious identity of Indonesian Muslims presents substantial barriers to accepting the doctrines of other faiths; thus, while material or educational support may function as useful means of ministry, they cannot be its ultimate purpose. The early church endured persecution by Jewish authorities and brutal oppression under imperial power, yet it persevered through the power of Scripture and the work of the Spirit. Ministry among Indonesian Muslims likewise cannot be sustained by human capability alone. It requires humble prayer, dependence on divine guidance, and the offering of one’s life in faithful service. This calling extends beyond ministry among Muslims to encompass the broader vocation of Indonesian churches: to recover spiritual fervor and serve the lost across nations.

References

Azra, A. (2004). The origins of Islamic reformism in Southeast Asia. Routledge.

Badan Pusat Statistik. (n.d.). Sensus penduduk Indonesia. https://sensus.bps.go.id/

Beatty, A. (1999). Varieties of Javanese religion: An anthropological account. Cambridge University Press.

Fealy, G., & White, S. (2008). Expressing Islam: Religious life and politics in Indonesia. Institute of Southeast Asian Studies.

Geertz, C. (1960). The religion of Java. University of Chicago Press.

Kementerian Agama Republik Indonesia. (n.d.). Jumlah penduduk menurut agama.https://satudata.kemenag.go.id/dataset/detail/jumlah-penduduk-menurut-agama

Pew Research Center. (2025). Global religious change report.https://www.pewresearch.org/wp-content/uploads/sites/20/2025/06/PR_2025.06.09_global-religious-change_report.pdf

Pires, T. (1990). The Suma Oriental. Laurier Books.

Ricklefs, M. C. (1993). A history of modern Indonesia since c. 1200. Stanford University Press.