Why Are There So Many Extremist Religious Groups? A Jewish, Christian, and Islamic Perspective

Judaism has grappled with internal fragmentation and zealotry for millennia. The Torah itself anticipates the danger of individuals or whole clans quietly drifting toward destructive ideologies, warning that such a person can become a stock sprouting poison weed and wormwood within the broader community Deuteronomy 29:17. The metaphor is agricultural and slow-burning — extremism doesn't usually announce itself; it grows underground.

The prophet Elijah's cry in 1 Kings is one of the most psychologically vivid portraits of religious extremism in any scripture. Convinced he's the last faithful person alive, he declares, "I alone am left, and they are out to take my life" I Kings 19:14. God's response is telling: Elijah is gently corrected and told 7,000 faithful Israelites remain. The rabbinical tradition, especially Maimonides in the 12th century, read this episode as a cautionary tale about the dangers of solitary, unchecked zeal — the conviction that I alone hold the truth is itself a spiritual pathology.

Modern Jewish scholars like Rabbi Jonathan Sacks (d. 2020) argued extensively that extremism is what happens when a religion loses its capacity for self-criticism and dialogue. The Talmudic culture of argument — machloket l'shem shamayim, disagreement for the sake of heaven — was designed precisely to prevent any single interpretation from calcifying into violent certainty. When that culture breaks down, extremism fills the vacuum.

Christianity doesn't have a single scriptural passage that directly explains why extremist groups proliferate, but its own history is arguably the most dramatic illustration of the phenomenon. From the Crusades to the Inquisition to 20th-century Christian nationalism, the tradition has repeatedly produced movements that claimed divine sanction for violence or coercion.

New Testament scholars like N.T. Wright and, earlier, Ernst Käsemann (writing in the 1960s) pointed to the tension built into early Christianity itself: a faith that claims universal truth will always attract people who want to enforce that truth on others. Paul's letters already show communities fracturing over doctrine, practice, and authority — a pattern that never really stopped.

Theologians like Reinhold Niebuhr (20th century) argued that religious extremism is a specific form of what he called the pride of power — the human tendency to absolutize finite perspectives. When a community believes it has direct, unmediated access to God's will, the psychological distance between conviction and coercion shrinks dramatically. Christian tradition does offer internal correctives — the concept of ecclesial humility, the Reformation emphasis on semper reformanda (always reforming), and liberation theology's insistence that the poor, not the powerful, are the measure of authentic faith — but these correctives are themselves contested, which is part of why fragmentation continues.

The Quran addresses religious fragmentation with unusual directness and frequency. It doesn't treat sectarianism as an unfortunate accident — it treats it as a predictable moral failure rooted in ego and tribalism. Surah 23:53 is blunt: "But they (mankind) have broken their religion among them into sects, each group rejoicing in its tenets" Quran 23:53. The Arabic word farihun (rejoicing, exulting) is pointed — the problem isn't just division, it's the self-satisfaction that comes with it.

Surah 30:32 reinforces this, describing those who "split up their religion and became schismatics, each sect exulting in its tenets" Quran 30:32. Islamic scholars like Ibn Khaldun (14th century) and, more recently, Khaled Abou El Fadl (contemporary) have argued that extremism emerges specifically when a community substitutes its own certainty for the humility that authentic faith demands. Abou El Fadl's 2001 work Conference of the Books traces how authoritarian interpretive cultures — where one group claims a monopoly on correct understanding — breed the conditions for extremism.

The Quran also acknowledges that diversity within the Muslim community is real: "And among us there are righteous folk and among us there are far from that. We are sects having different rules" Quran 72:11. This verse, notably spoken by jinn rather than humans, is sometimes read as a frank admission that no community, however devout, is monolithic. The tradition's internal debate about takfir (declaring fellow Muslims apostates) is directly relevant here — most classical scholars treated it as one of the most dangerous tendencies in Islamic thought precisely because it provides theological cover for violence against co-religionists.

Jewish scripture warns that when hearts turn from the covenant toward alien loyalties, a bitter root can sprout within the community, which the text metaphorically names “poison weed and wormwood,” signaling internal corruption that can manifest in extreme tendencies Deuteronomy 29:17.

Elijah’s repeated cry, “I am moved by zeal,” shows how fervor can become isolating and violent when coupled with the belief that one is the last true adherent, a profile often seen in extremist postures where dissenters are treated as enemies 1 Kings 19:10. The narrative registers that such zeal arises amid covenantal breakdown and communal fear, not as a normative ideal 1 Kings 19:14.

Christian readings of the shared Old Testament likewise see the danger of zeal untethered from covenantal faithfulness and mercy, as Elijah’s lament illustrates: intense zeal alongside a narrative of isolation can foster violent antagonism toward perceived apostates 1 Kings 19:10.

The same Deuteronomic image of a community growing a bitter root warns Christians that inner defection from God’s ways can yield harmful offshoots—an apt scriptural diagnosis for factions that elevate partial truths into absolute agendas Deuteronomy 29:17. Christian interpreters have long cautioned that such zeal, without correction and humility, fractures the community and imperils life, as the text’s account of slain prophets underscores 1 Kings 19:14.

The Qur’an states that people have split their religion into sects, with each group rejoicing in its own tenets, identifying a human tendency toward factionalism that can harden into extremism when self-congratulation replaces shared guidance Quran 23:53.

It similarly describes those who “split up their religion and became schismatics,” highlighting how division itself becomes an identity marker that fuels rivalry and excess Quran 30:32. Another passage notes that among jinn (and by extension communities) there are the righteous and others far from that, acknowledging moral divergence and the emergence of differing rules, which can enable extreme strands if not disciplined by revelation and justice Quran 72:11.