Christianity: History, Beliefs, and Practices

A carpenter’s son from a small Galilean village never wrote a book, never commanded an army, and never traveled more than a hundred miles from his birthplace. Yet within three centuries of his death, a movement bearing his name had spread across the Roman Empire. Within a millennium, it had reshaped Europe. Today, nearly one in three people on Earth identify as Christian. The story of Christianity begins with Jesus of Nazareth, but it does not end there — it is a story of persecution and power, division and renewal, ancient texts and living faith.

The Historical Foundations

The Life of Jesus

Jesus was born around 4 BCE in Bethlehem, then a small town in Judea, a province of the Roman Empire. The Gospels — Matthew, Mark, Luke, and John — provide the primary accounts of his life and teachings. They portray him as a Jewish teacher who gathered disciples, performed healings, and proclaimed the coming of the Kingdom of God. His teachings, distilled in the Sermon on the Mount, emphasized love of God and neighbor, forgiveness of enemies, and care for the poor and marginalized.

Jesus’s public ministry lasted roughly three years. His radical message and growing following alarmed both Roman authorities and Jewish religious leaders. Around 30 CE, he was arrested, tried, and crucified — a common Roman punishment for rebels and criminals. According to Christian belief, three days after his death, his tomb was found empty, and he appeared to his disciples, resurrected. This event, the Resurrection, is the cornerstone of Christian faith.

The Early Church

After Jesus’s ascension, his disciples began preaching in Jerusalem and beyond. The Apostle Paul, a former persecutor of Christians who experienced a dramatic conversion, became Christianity’s most influential missionary. His letters to early Christian communities form a substantial part of the New Testament. The early church grew rapidly despite — or perhaps because of — periodic persecution by Roman authorities. Christians were blamed for natural disasters, accused of atheism for refusing to worship Roman gods, and sometimes executed in spectacular ways.

The turning point came in 312 CE when the Emperor Constantine claimed to have seen a vision of the cross before battle. The following year, the Edict of Milan legalized Christianity. By the end of the fourth century, under Emperor Theodosius I, Christianity became the official religion of the Roman Empire.

Core Beliefs

The Trinity

The doctrine of the Trinity defines Christianity’s understanding of God: one God existing eternally in three persons — Father, Son, and Holy Spirit. This is not tritheism (three gods) but a mystery of unity and distinction. The Father is the source of all being, the Son (Jesus Christ) is God incarnate, and the Holy Spirit is God’s active presence in the world and in believers. The Nicene Creed, formulated in 325 CE, remains the definitive statement of Trinitarian orthodoxy across Catholic, Orthodox, and Protestant traditions.

Salvation and Grace

Central to Christian theology is the belief that humanity is separated from God by sin — a condition of alienation that cannot be overcome by human effort alone. Salvation comes through God’s grace, made possible by Jesus’s sacrificial death on the cross. As the Gospel of John puts it, “God so loved the world that he gave his only Son, that whoever believes in him should not perish but have eternal life.” Christians differ on the mechanics of salvation: Catholics emphasize faith and sacraments, Protestants often stress faith alone (sola fide), and Orthodox Christians focus on theosis — the gradual transformation of the believer into the likeness of God.

The Bible

The Christian Bible consists of the Old Testament (shared with Judaism) and the New Testament (unique to Christianity). The Old Testament contains books of law, history, poetry, and prophecy. The New Testament includes the four Gospels, the Acts of the Apostles, the Epistles (letters), and the Book of Revelation. Catholic and Orthodox Bibles also include the Deuterocanonical books, which Protestants regard as apocryphal. The Bible is considered by most Christians to be divinely inspired, though interpretations of its authority and inerrancy vary widely.

The Sacraments

Sacraments are visible signs of inward grace. Most Christian traditions recognize baptism and the Eucharist (Communion, Lord’s Supper) as central. Baptism, typically involving water, marks initiation into the Christian community and symbolizes spiritual cleansing and rebirth. The Eucharist commemorates Jesus’s last meal with his disciples, in which he identified bread and wine with his body and blood. Catholic and Orthodox traditions also recognize confirmation, penance, anointing of the sick, holy orders, and marriage as sacraments.

Major Traditions

Christianity has three major branches. The Roman Catholic Church, led by the Pope in Vatican City, is the largest with over 1.3 billion members. Eastern Orthodoxy, comprising several autocephalous churches (Greek, Russian, Antiochian, among others), split from Rome in the Great Schism of 1054 over questions of papal authority and theological differences. Protestantism emerged from the Reformation of the sixteenth century, when figures like Martin Luther, John Calvin, and Huldrych Zwingli challenged Catholic teachings on grace, scripture, and church authority. Protestantism has since splintered into thousands of denominations, including Lutherans, Anglicans, Baptists, Methodists, Presbyterians, and Pentecostals.

Christian Practices

Prayer is the most universal Christian practice, ranging from spontaneous personal prayer to the structured liturgy of the Divine Office or the Rosary. Worship services typically include scripture readings, a sermon, prayers, and hymns or contemporary music. Major Christian holidays include Christmas (celebrating Jesus’s birth) and Easter (celebrating his resurrection). Lent, the forty-day period of fasting and reflection before Easter, and Advent, the preparation for Christmas, are observed by Catholics, Orthodox, and many Protestants.

Christianity in Global Context

Christianity is no longer primarily a Western religion. While Europe and North America have seen declining church attendance, Christianity is growing rapidly in the Global South. Africa, which had roughly 10 million Christians in 1900, now has over 600 million, and some projections suggest Africa will be the center of global Christianity by 2050. Pentecostalism, characterized by emphasis on the Holy Spirit, miraculous healing, and ecstatic worship, is the fastest-growing Christian movement, with over 600 million adherents worldwide. Latin America, historically Catholic, has seen significant growth of Protestant and Pentecostal churches. In Asia, Christianity is a minority faith but growing in China, South Korea, and India.

The Orthodox tradition, centered in Eastern Europe, Russia, and the Middle East, maintains ancient liturgical practices and a decentralized structure of independent national churches. The Ecumenical Patriarch in Constantinople holds honorary primacy but does not exercise the kind of authority the Pope holds in Catholicism. The Russian Orthodox Church, the largest Orthodox church, has played a significant role in post-Soviet Russian identity and politics.

Christianity has profoundly shaped Western civilization. Its teachings influenced the development of hospitals, universities, and human rights. Christian art, from Michelangelo’s Sistine Chapel to gospel music, represents some of humanity’s greatest creative achievements. The faith has also been implicated in colonialism, religious wars, and persecution — a complex legacy that believers continue to wrestle with. The social gospel movement, emerging in the late nineteenth century, emphasized applying Christian ethics to social problems like poverty, inequality, and labor exploitation, influencing progressive reforms worldwide. Liberation theology, developed in Latin America by theologians like Gustavo Gutiérrez, interpreted Christian salvation as encompassing political and economic liberation of oppressed peoples. For a broader context on how Christianity relates to other faiths, see World Religions: An Overview.

Christianity’s global diversity reflects its ability to adapt across cultures while maintaining core beliefs. From Ethiopian Orthodox traditions dating to the fourth century to Korean megachurches and Latin American base communities, Christianity continues to evolve as a truly global faith shaped by local contexts.

FAQ

What do Christians believe about God?

Christians believe in one God who exists as three persons — Father, Son, and Holy Spirit. God is understood as eternal, all-powerful, all-knowing, and perfectly loving, who created the universe and desires relationship with humanity.

Why is Jesus’s resurrection important?

The resurrection is the central claim of Christianity. It validates Jesus’s identity as the Son of God, demonstrates his victory over sin and death, and guarantees eternal life for believers. As Paul wrote, “If Christ has not been raised, your faith is futile.”

What is the difference between Catholicism and Protestantism?

Key differences include authority (Catholics recognize the Pope and church tradition alongside scripture; Protestants emphasize scripture alone), sacraments (Catholics recognize seven, most Protestants two), and salvation (differing views on faith, works, and grace). The Reformation of the 1500s produced the Protestant-Catholic divide.

Do Christians believe non-Christians go to hell?

Views vary widely. Some traditions teach that explicit faith in Christ is necessary for salvation. Others, including many Catholics and mainline Protestants, hold that sincere followers of other religions or those who never heard the gospel may be saved through God’s mercy.

What is the most widely used Christian prayer?

The Lord’s Prayer (“Our Father, who art in heaven…”) is the most universal Christian prayer, taught by Jesus himself. It is used across all traditions in worship and private devotion.