Introduction

Religious life in Indonesia over the past decades has demonstrated increasingly complex dynamics. On the one hand, religious awareness and spiritual practices have grown significantly, as reflected in the expansion of religious institutions and activities. On the other hand, this development has been accompanied by the rise of intolerance, extremism, and radicalism that threaten social cohesion and national unity. In the Indonesian context, these challenges pose serious risks to the integrity of the Unitary State of the Republic of Indonesia (NKRI), particularly within pluralistic and multicultural settings.

The escalation of intolerance and radicalism cannot be separated from global and digital transformations. Social media platforms have become powerful arenas for the dissemination of religious narratives, including exclusive and extremist ideologies. Ideological echo chambers are frequently strengthened by algorithm-driven content distribution, which exacerbates polarization and restricts exposure to opposing viewpoints [1], [2]. Further research shows that moral contagion and the construction of group identities in digital environments encourage people, particularly young people, to adopt strict religious stances, making them more vulnerable to radical ideas [3], [4].

These dynamics are especially troubling in societies with a wide range of religious beliefs, like Indonesia. According to research, strict readings of religious texts that are spread via digital media undermine pluralism and foster exclusive views [5], [6]. Students and young people are among the most susceptible individuals exposed to extremist narratives, according to empirical research, particularly in urban areas and religiously affiliated educational institutions [7]. This fact emphasizes how urgently educational institutions must serve as both hubs for religious knowledge and places to foster inclusive religious understanding and tolerance.

In this regard, religious moderation has been a key tactic in Islamic education. Religious moderation, which has its roots in the Islamic concept of wasatiyyah, places an emphasis on harmony, inclusivity, communication, and respect for variety. In order to promote peaceful cohabitation in a pluralistic society, religious moderation has been emphasized more and more in Indonesian educational programs [8], [9], [10]. Therefore, it is anticipated that Islamic education will go beyond only imparting doctrine and actively support the development of character that incorporates social duty, citizenship, and faith.

Islamic boarding schools (pesantren), as the oldest Islamic educational institutions in Indonesia, occupy a strategic position in this endeavor. Historically, pesantren have played a crucial role in shaping religious consciousness grounded in local wisdom, national commitment, and social harmony. Their educational philosophy integrates deep religious understanding (tafaqquh fiddin) with moral discipline, communal life, and social engagement, enabling students to internalize religious values through daily practices and role modeling [11], [12]. This holistic system positions pesantren as effective institutions for nurturing moderate and balanced religious attitudes.

Moreover, pesantren function not merely as formal educational institutions but as socio-cultural communities where values are transmitted through formal curricula, hidden curricula, and lived experiences. Character education in pesantren is reinforced through routines such as communal worship, study of classical Islamic texts (kitab kuning), discipline, and close mentorship between teachers (kyai) and students (santri) [13], [14]. These behaviors aid in the internalization of principles that are essential to religious moderation, such as tolerance, respect, discipline, and social responsibility.

Notwithstanding their advantages, pesantren also struggle to internalize religious restraint in modern settings. Curriculum restrictions, opposition to moderation terminology, a lack of interreligious connection because of homogeneous surroundings, and the requirement to adjust to digital reality are some of the constraints [15]. Nevertheless, pesantren demonstrate considerable adaptability by integrating digital literacy, inclusive pedagogical approaches, and community engagement to counter radical narratives and promote moderate Islamic values [16], [17].

Therefore, this study aims to systematically examine the existence and role of Islamic boarding schools in the internalization of religious moderation values through a Systematic Literature Review (SLR). By synthesizing empirical findings and theoretical perspectives, this research seeks to provide a comprehensive understanding of how pesantren contribute to fostering religious moderation and safeguarding national unity in the contemporary era. Ultimately, this study affirms that pesantren are not only religious educational institutions but also vital socio-national entities that play a strategic role in strengthening inclusive, moderate, and peaceful religious life in Indonesia.

Method

This study employed a Systematic Literature Review (SLR) as the primary research method to examine and synthesize existing scholarly works related to the internalization of religious moderation values in Islamic boarding schools (pesantren) and their contribution to maintaining national unity in Indonesia. Because it allows for a thorough, organized, and evidence-based summary of the state of research in a particular topic, the SLR approach was chosen. SLR is a type of secondary research that is especially suitable for examining various educational practices and conceptual frameworks within Islamic education because it makes it easier to find, assess, and interpret pertinent empirical studies through transparent and repeatable procedures.

Instead of gathering primary data through surveys or tests, the study concentrated on a thorough analysis of peer-reviewed journal papers published between 2021 and 2025 that were indexed in Sinta 2-4. Thematic analysis was used to thoroughly study and analyze a total of 17 publications that satisfied the inclusion criteria. The three primary phases of the analysis were: thematic coding and categorization to find recurrent concepts like digital moderation, integrative curricula, kyai leadership, moderate character education, and the social roles of santriin plural societies; interpretative synthesis based on theories of religious moderation and contextual Islamic education; and data reduction through repeated reading and classification of findings. This process resulted in a conceptual framework illustrating the relationship between pesantren education, the internalization of religious moderation values, and the reinforcement of national cohesion, which is presented narratively in the results and discussion sections.

Results and Discussion

A. The Epistemological Existence of Islamic Boarding Schools in Internalizing Religious Moderation Values

The systematic review of seventeen peer-reviewed articles published between 2021 and 2025 demonstrates that Islamic boarding schools (pesantren) possess a strong epistemological foundation in internalizing religious moderation values. Pesantren are regularly depicted in the examined literature as dynamic educational spaces where Islamic teachings, local wisdom, and national values converge, rather than just as traditional religious institutions. Pesantren are positioned as agents of value transformation rather than merely religious information bearers in this epistemological capacity. A long-standing history of striking a balance between social harmony and doctrinal faith is shown in the incorporation of religious moderation within pesantren education. Consequently, pesantren contribute significantly to shaping moderate religious attitudes rooted in both Islamic principles and Indonesian pluralism.

Several studies emphasize that pesantren function as moral and intellectual ecosystems where moderation is cultivated through lived experiences rather than abstract discourse. Research by Islam & Azizz and Sutomo & Syukur highlights pesantren as spaces for nurturing wasathiyah communities that prioritize justice, tolerance, and balance [18], [19]. These principles are ingrained in regular educational procedures and social interactions rather than being taught directly as discrete ideas. Santri integrate moderation as a way of life through group education, community devotion, and disciplined lifestyles. The idea that religious moderation in pesantren is epistemically anchored rather than externally enforced is strengthened by this procedure.

Maula further points out that through classical Islamic study and ethical growth, pesantren traditions promote respect for diversity, both within and between religions [20]. According to the study, disagreements over jurisprudential views (ikhtilaf) are presented as sources of intellectual diversity rather than conflict. Islamic teachings, which place a strong emphasis on mutual understanding and coexistence, are consistent with such epistemological openness. Pesantren graduates typically demonstrate social flexibility and inclusive religious attitudes as a result. These results confirm that the internalization of religious moderation norms is intrinsically supported by pesantrenepistemology.

B. Pedagogical Strategies and Educational Practices Supporting Religious Moderation

The reviewed literature reveals that pesantren employ diverse pedagogical strategies to strengthen religious moderation amid globalization and digital transformation. One prominent strategy is the integration of moderation values into formal curricula, particularly within Islamic studies and civic education. Studies by Shalahuddin et al, Kohar et al, Amalia, and Zubaidi et al show that pesantren embed national values alongside religious teachings to cultivate balanced religious-national identities [15], [21], [22], [23]. Moderation is presented as both a civic duty and a religious duty because to this curriculum integration. These strategies show how versatile Pesantren is in addressing today's sociopolitical issues.

Pesantren places a strong emphasis on model leadership and role modeling in addition to curriculum development. Santri's character development is greatly influenced by the attitudes and actions of the kyai and teachers, who act as moral role models. Research repeatedly shows that uswah hasanah, as opposed to didactic training alone, is the most effective way to spread moderation values. Santri examine how religious knowledge is applied with wisdom, tolerance, and humility via everyday encounters. The internalization of moderation as an ethical tendency rather than a theoretical concept is strengthened by this social education.

Additionally, as part of their teaching methods, pesantren has been incorporating media participation and digital literacy more and more. Studies by Anwar et al and Fauzi et al highlight pesantren’s use of social media platforms to disseminate moderate Islamic narratives and counter extremist content [24], [25]. In response to digital radicalization and online echo chambers, pesantren promote ethical communication and critical media literacy. This proactive engagement transforms digital spaces into arenas for peace-oriented religious discourse. Consequently, pesantren extend their educational influence beyond physical boundaries into the digital public sphere.

C. Contribution of Pesantren-Based Moderation to National Unity and Social Cohesion

The internalization of religious moderation within pesantren significantly contributes to strengthening national unity and social cohesion in Indonesia. Literature consistently demonstrates that pesantren integrate religious education with a strong sense of nationalism, framing loyalty to the nation as part of religious devotion. Through teachings that emphasize social justice, tolerance, and collective responsibility, pesantren cultivate citizens who respect diversity and uphold democratic values. This educational orientation reinforces the idea that Islam and nationalism are complementary rather than contradictory. As a result, pesantren serve as moral pillars supporting Indonesia’s pluralistic society.

Several studies, including those by Mukarrom and Kohar et al, indicate that pesantren-based moderation education equips santri with dialogical skills necessary for navigating multicultural environments [15], [26]. Santri are encouraged to engage constructively with differences and to resolve conflicts through deliberation rather than confrontation. This strategy strengthens resistance to intellectual extremism and sectarianism. Pesantren lessens social division by encouraging inclusive interpretations of Islam. Their graduates frequently take on active roles as community leaders and mediators who promote harmonious cohabitation.

Additionally, by opposing extremist beliefs that jeopardize social harmony, pesantrensupport national integrity. According to the literature, moderation based on pesantren serves as a kind of cultural resistance against radical narratives, especially those propagated by digital media. By embedding moderation within institutional culture and daily practices, pesantren offer a sustainable model of counter-radicalization. This contribution is especially vital in addressing youth vulnerability to radical propaganda. Hence, pesantren play a strategic role in safeguarding the unity of the Republic of Indonesia through education rooted in moderation.

D. Supporting and Inhibiting Factors in the Internalization of Religious Moderation

The success of religious moderation internalization in pesantren is influenced by a complex interplay of supporting and inhibiting factors. Among the key supporting factors is charismatic and ethical leadership, particularly the role of the kyai as a moral authority. Studies emphasize that strong leadership fosters institutional coherence and reinforces moderation values across educational activities. Furthermore, the disciplined, respectful, and communal lifestyle of pesantrenculture fosters an atmosphere that is favorable to internalizing values. Pesantren's ability to encourage moderation is further strengthened by government backing and policy congruence.

On the other hand, the internalization process is hindered by a number of circumstances. In certain pesantrencommunities, the word "religious moderation" is met with resistance since it is seen as a contemporary or outsider discourse. Effective implementation is further hampered by a lack of human resources with a thorough grasp of moderation concepts. Furthermore, pesantrenhabitats are seriously threatened by the widespread influence of radical internet materials and transnational ideology. Strategic solutions are needed to overcome these obstacles and maintain the resilience of moderation values.

The literature suggests enhancing digital literacy, increasing institutional cooperation, and strengthening Islamic education's epistemological foundation in order to overcome these challenges. Enhancing educators’ competencies through continuous training is also considered essential. Collaborative engagement with communities and state institutions further reinforces pesantren’s role as moral guardians. Through these measures, pesantren can sustain their moderating function amid evolving social challenges. Ultimately, pesantren remain vital institutions for nurturing balanced religious understanding and national harmony.

Conclusion

This systematic literature review demonstrates that Islamic boarding schools (pesantren) possess a strong epistemological and institutional foundation in internalizing religious moderation values within the Indonesian context. The reviewed studies consistently indicate that pesantren function not only as traditional centers of Islamic learning but also as transformative educational institutions that integrate religious teachings, local wisdom, and national values. Pesantrensuccessfully fosters moderate, inclusive, and tolerant religious views in pupils through comprehensive educational approaches that include curriculum design, exemplary kyai leadership, everyday communal life, and adaptive interaction with digital media. Thewasathiyahepistemology, which emphasizes fairness, balance, and contextual interpretation of Islamic teachings in response to modern social difficulties, is reflected in these rituals.

Additionally, the Republic of Indonesia's unity and social cohesiveness are greatly enhanced by the internalization of religious moderation in pesantren. Pesantren promotes a peaceful balance between Islamic identity and national belonging by presenting religious moderation as both a civic duty and a theological commitment. Pesantren exhibit resilience and adaptation through instructional innovation, digital literacy, and institutional collaboration in the face of obstacles such opposition to moderation discourse, a lack of human resources, and the influence of global radical ideologies. Therefore, pesantren emerge as strategic socio-religious institutions capable of sustaining peace, tolerance, and national integrity amid globalization and digital transformation, while also offering a relevant educational model for promoting religious moderation in plural societies.