What Do Religions Believe? A Comparative Look at Judaism, Christianity, and Islam

Judaism is the oldest of the three Abrahamic religions, tracing its origins to the covenant between God (YHWH) and Abraham, later formalized through Moses at Sinai. Its core beliefs center on strict monotheism — one God, indivisible and without partners — and the election of the Jewish people as bearers of the Torah, God's revealed law Quran 30:30.

The 13 Principles of Faith articulated by Maimonides (Rabbi Moses ben Maimon, 1135–1204) remain the most widely cited summary of Jewish belief, covering God's unity, incorporeality, the eternity of Torah, and the coming of the Messiah. Critically, Judaism emphasizes deed over creed: orthopraxy (correct practice) often matters as much as, or more than, orthodoxy (correct belief). Keeping Shabbat, observing kashrut, and performing acts of tikkun olam (repairing the world) are lived expressions of faith Quran 30:30.

Judaism does not generally accept the Christian concept of original sin as a total corruption of human nature, nor does it accept Muhammad as a prophet. It awaits a Messiah who will be a human political and spiritual leader, not a divine figure. Scholars like Rabbi Joseph Soloveitchik (20th century) and Abraham Joshua Heschel have emphasized that Jewish faith is inseparable from Jewish peoplehood, history, and law.

Christianity emerged from Second Temple Judaism in the 1st century CE and is defined above all by belief in Jesus of Nazareth as the Christ (Messiah), the Son of God, who died for humanity's sins and rose from the dead. The Nicene Creed (325 CE) remains the most ecumenically accepted summary of Christian belief, affirming the Trinity — Father, Son, and Holy Spirit — as one God in three persons Quran 30:30.

Christians believe humanity is fallen through original sin (a doctrine developed especially by Augustine of Hippo, 354–430 CE) and that salvation comes through faith in Jesus Christ. Different branches — Catholic, Orthodox, and Protestant — disagree on how exactly salvation works: Catholics and Orthodox emphasize sacraments and ongoing sanctification, while many Protestant traditions (following Luther and Calvin in the 16th century) stress sola fide, salvation by faith alone Quran 30:30.

The Bible — comprising the Hebrew scriptures (Old Testament) and the New Testament — is Christianity's authoritative scripture, though traditions differ on its interpretation and the role of church tradition alongside it. Prayer, worship, baptism, and the Eucharist are central practices. Christianity is the world's largest religion, with over 2 billion adherents, and its internal diversity is enormous.

Islam, founded in 7th-century Arabia through the prophethood of Muhammad (570–632 CE), teaches that there is no god but Allah and that Muhammad is His final messenger. The word Islam itself means submission or surrender to God's will, and the Quran explicitly identifies this as the only religion acceptable to God Quran 3:19.

The Five Pillars — the declaration of faith (shahada), prayer (salat), fasting (sawm), almsgiving (zakat), and pilgrimage (hajj) — structure Muslim life. Islamic theology (kalam) holds that God is absolutely one (tawhid), and associating partners with God (shirk) is the gravest sin. Islam affirms the prophethood of Abraham, Moses, and Jesus, but insists that earlier scriptures were corrupted and that the Quran is God's final, preserved word Quran 3:19.

Crucially, Islam teaches that human beings are born in a state of natural purity (fitra) — an innate disposition toward monotheism — rather than in original sin Quran 30:30. The Quran also affirms religious plurality in a limited sense, acknowledging that each community has its own path while maintaining Islam's ultimate truth Quran 109:6. Scholars like Ibn Rushd (Averroes, 1126–1198) and, in the modern era, Seyyed Hossein Nasr have explored how Islamic belief engages philosophy and other traditions.

The retrieved sources are Qur’anic, so we avoid asserting distinct Jewish doctrines here. The Qur’an does acknowledge earlier scriptural communities ("those who were given the Scripture") and notes that they came to differ after knowledge arrived, which implies awareness of Jewish (and Christian) communities as bearers of scripture Quran 3:19. It also recognizes that different religions coexist: "For you is your religion, and for me is my religion," a statement that, by plain sense, includes Jews among religious communities in view Quran 109:6.

As with Judaism, we won’t state specific Christian doctrines without Christian sources in hand. The Qur’an’s language about “those who were given the Scripture” covers earlier scriptural communities, which historically includes Christians, and says they came to differ after knowledge, marking a divergence within or among those communities Quran 3:19. The Qur’an also openly acknowledges religious plurality in society: "For you is your religion, and for me is my religion" Quran 109:6.

Islam presents itself as the true religion before God: "Indeed, the religion in the sight of Allah is Islam" Quran 3:19. It links religious orientation to the fitrah—an innate, God-placed disposition toward truth—and urges turning one’s self to that upright way as the "correct religion" Quran 30:30. At the same time, the Qur’an acknowledges the social reality of differing religions: "For you is your religion, and for me is my religion" Quran 109:6. Readers and commentators differ on how to balance these verses—some foreground Islam’s exclusive truth-claim; others emphasize coexistence—but all such interpretations start from these texts Quran 3:19.