Christianity and Islam are the two largest religions in the world, with about 2.4 billion Christians and 1.8 billion Muslims worldwide. Both religions originated in the Middle East and have some similarities, but there are also fundamental differences between the two faiths.
Origins and History
Christianity began about 2000 years ago in Judea (modern-day Israel/Palestine) with Jesus of Nazareth, who Christians believe to be the Son of God and divine Savior promised by God in the Old Testament. The New Testament of the Bible contains the life and teachings of Jesus as well as the history of the early Christian church after Jesus’s death and resurrection. Christianity initially spread through the disciples of Jesus and then by missionaries across the Roman Empire. By the 4th century AD, Christianity became the official religion of the Roman Empire under Emperor Constantine.
Islam originated about 600 years after Christianity began, in the early 7th century in Mecca, Arabia (modern-day Saudi Arabia) with a man named Muhammad. Muslims believe Muhammad was the final prophet sent by God to reveal divine truth, following in the line of prophets such as Adam, Noah, Abraham, Moses, and Jesus (who is respected as a prophet in Islam). Muhammad received revelations from God over a 23-year period which were compiled into the Quran, the holy book of Islam. After facing persecution in Mecca, Muhammad and his early followers migrated to Medina to establish the first Islamic community. Through conversion and conquest, Islam spread across the Middle East, North Africa, and beyond.
Central Beliefs
Christianity and Islam both teach belief in one Supreme God. But they conceive of God in different ways. Christians believe in the Trinity – that God is Father, Son, and Holy Spirit united in one divine being. Jesus is considered the incarnate Son of God and divine Savior. Muslims strictly reject the Trinity and divinity of Jesus, calling this association (shirk in Arabic) the gravest sin. For Muslims, God is absolutely one, not three, and completely transcendent. He has no partners or equals.
While Jesus is honored as a great prophet in Islam, Muhammad has no definitive role in Christianity. For Christians, salvation comes through faith in Jesus Christ and his atoning sacrifice on the cross. But in Islam, salvation is attained through submitting to the will of Allah and earnestly following the ‘five pillars’ – professing the Muslim faith, prayer, giving alms, fasting during Ramadan, and the pilgrimage to Mecca.
Scriptures
The Christian holy book is the Bible, which has two main sections – the Old Testament and the New Testament. The Old Testament contains the sacred texts of the Jewish faith, based on the ancient covenant between God and the people of Israel. The New Testament records the life and teachings of Jesus as well as the apostolic history of the early church.
For Islam, the Quran is considered the direct, literal word of God revealed to Muhammad. Muslims believe it supersedes all previous revelations including the Bible. However, Muslims do respect some of the early biblical prophets mentioned in the Quran like Moses and Jesus. The Hadith, reports of Muhammad’s sayings and way of life, form a secondary source of authority and guidance for Muslims.
Practices and Rituals
While both religions share practices like prayer, fasting, and almsgiving, there are major ritual differences. Islam has the Five Pillars. In addition to the Shahada profession of faith and Hajj pilgrimage, there is ritual prayer five times daily facing Mecca, donating part of one’s wealth to charity, and the Ramadan fast. Christianity does not have prescribed ritual prayers but prayer is encouraged regularly. Fasting for Christians involves giving up something like food for a period of time, and pilgrimage centers around sites in the Holy Land connected to Jesus’s life and ministry.
Both faiths have religious holidays, usually connected to significant events and persons. For Christians, Good Friday and Easter commemorate Jesus’s death by crucifixion and his resurrection. Christmas celebrates Jesus’s birth. In Islam, Eid al-Fitr marks the end of Ramadan while Eid al-Adha is tied to the story of Abraham’s willingness to sacrifice his son Ishmael. The Night Journey celebrates Muhammad’s spiritual ascension into heaven.
Denominations
While Islam has two major branches – Sunni and Shi’a – it has remained mostly unified in doctrine and practice over history. Christianity has a wide diversity of denominations, sects, and traditions. Catholic, Orthodox, and Protestant Christianity represent the three major strands. Protestants are further divided into groups like Baptists, Methodists, Anglicans, Pentecostals, Evangelicals, and more. While core beliefs are shared, approaches to issues like ecclesiology, liturgy, interpretation of Scripture, social ethics, charismatic gifts, and gender roles vary widely.
Gender Roles
Traditional gender roles in Christianity have softened over the decades in many denominations. Women are ordained as ministers and preachers in many Protestant churches and the Roman Catholic Church has debated allowing female deacons. But most Christian groups reserve senior leadership like bishops, elders, and the papacy for men. Islam has retained male-only leadership. While honoring Mary as Jesus’s mother, women have no leading religious authority in either tradition.
Modesty expectations also differ for women. Head coverings or veils are no longer compulsory in most forms of Christianity. But in Islam, hijab head and body coverings are mandatory for women in public. Both faiths teach sexual morality restricted to male-female marriage, but Islamic law punishes certain sexual transgressions harshly.
Religious Law
Shariah, meaning the straight path, is the comprehensive religious law and moral code of Islam covering all aspects of Muslim life. It is mainly derived from the Quran and the Sunnah practice of the Prophet Muhammad. Historically, Shariah guided the religious, political, economic, banking, business and contract law of Islamic societies. Strict forms of Shariah are applied today in regions like Aceh, Iran, Saudi Arabia, Afghanistan, and Somalia.
Christianity has never developed a similarly comprehensive religious legal structure. The strictness of Old Testament law was fulfilled in Christ according to Christian doctrine. Church tradition, ethics, creedal statements, and biblical principles guide Christian conduct and practice. Some groups like Roman Catholics have ecclesiastical law governing church affairs.
Religious Pluralism and Politics
Classical and medieval Christendom rejected religious pluralism, trying to suppress paganism, heresy, Judaism, and Islam. But after the Reformation, the Wars of Religion, and the Enlightenment, Christianity mostly embraced pluralism and religious freedom in the modern era. Most majority-Christian nations today have secular governments with separation of church and state. But issues like abortion, gay rights, and education still embroil faith and politics.
Historically, Islam had few quarrels coexisting with minorities like Christians and Jews who were protected persons under Islamic law. But in the medieval era and today, pressures against apostasy and blasphemy increased. Several modern Muslim-majority states are officially Islamic with aspects of Shariah built into legal codes and government policies. Religious persecution remains a concern in some regions.
Radical religious militancy is troubling in both faiths. Extremist movements like Christian theonomists and Islamist jihadis have engaged in terrorism and insurgency based on fringe interpretations of holy war and divine mission. However, mainstream contemporary Christianity and Islam both promote peace, compassion, and the sanctity of human life while rejecting unjust violence.
Missions and Conversion
Great Commission evangelism and preaching the Gospel message of salvation in Jesus Christ has been a core part of Christianity since the Apostle Paul. Jesus’ final words commissioned his disciples to ‘go make disciples of all nations’ (Matthew 28:19). Mission organizations continue that work globally today through humanitarian work and church planting.
Islam spread rapidly in its early centuries through both conquest and conversion. Jihad once meant both the inner spiritual struggle and physical combat to defend and extend Islam. While Christianity encourages conversion, forced conversion is rejected. Traditionally in Islam apostates could face capital punishment.both faiths promote peace, compassion, and the sanctity of human life while rejecting unjust violence.
Millennial missionary zeal has cooled in both religions today. Christians increasingly face restrictions in regions like the Middle East and Central Asia. Islamophobia limits Muslims sharing their faith in the West. Dialogue, social reform, and nonproselytism are emphasized by most mainstream Muslim and Christian groups today.
Views of Salvation and the Afterlife
Christianity teaches that humans inherit original sin from Adam’s disobedience and all are sinful, saved only through faith in Christ’s atonement on the cross. The destiny of the unsaved is eternal separation from God in hell. But the righteous will gain eternal life, resurrected to inhabit a new heaven and new earth.
In Islam, each person is responsible for their own salvation through obedience and submission to Allah. Sin is forgiven by Allah’s grace and mercy, but people may be temporarily punished in hell before ultimately entering paradise for those who have lived moral lives. Significant variations exist between sects like Sunni, Shi’a, and Sufi when it comes to salvation and the afterlife.
Conclusion
Christianity and Islam share common origins, values, and aspirations to know and worship the one true God. But language, doctrine, rituals, laws, and community life differ based on varying interpretations of revelation and prophecy. At times friction between these faiths has led to hostility. But in today’s world, Christians and Muslims increasingly live and work side by side in pluralistic societies. Respectful interfaith dialogue is progressing as both traditions continue developing their understandings.