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Religious Studies · Foundations

Christianity

9 min read 5 practice questions
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On this page 9 sections
  1. In 30 seconds
  2. Why this matters
  3. The college version
  4. Eli explains
  5. Worked example
  6. Key takeaway
  7. Quick check
  8. Study tools
  9. Sources & references

In 30 seconds

Christianity is the world's largest religion, with over two billion followers, and one of the most geographically widespread. It centers on Jesus of Nazareth, a Jewish teacher of the early first century CE whom Christians identify as the , the Messiah. Core beliefs include the of Father, Son, and Holy Spirit, and the claims of , , and , described here as central claims of the tradition. Its scripture is the Bible: the and the , including the Gospels. Major branches include Roman Catholic, Eastern Orthodox, and Protestant churches, alongside newer global movements.

Why this matters

Christianity shapes institutions, art, ethics, and calendars across much of the world, so recognizing its internal diversity is basic literacy for studying history, culture, and current events. Because the tradition spans Catholic, Orthodox, and Protestant churches and now grows fastest in Africa, Asia, and Latin America, a single-sentence description of what Christians believe will mislead. Studying Christianity descriptively trains students to report what adherents and scholars say without adjudicating between them, a skill every later religious-studies lesson will reuse. It also prepares students for the sibling topics on Judaism and Islam, the other Abrahamic traditions, with which Christianity shares texts, stories, and a region of origin.

The college version

Origins: Jesus of Nazareth and the movement around him

Christianity is rooted in the life, teachings, and death of Jesus of Nazareth in the early first century CE, a framing scholars and the tradition itself share. Jesus was a Jewish teacher in the Roman-ruled land of Judaea. Britannica describes his public ministry as that of an itinerant preacher and healer; in the tradition's account he was born in Bethlehem and raised in Nazareth. OpenStax's sociology survey tells the same story: Christianity began about two thousand years ago in the Middle East with Jesus of Nazareth, who taught followers to treat others as they would like to be treated. A movement of followers formed around him; after his execution by crucifixion, a Roman method of capital punishment, it kept growing and spreading. Christians identify Jesus as the Christ, the Messiah they believe the Old Testament promised. Scholars date his life's details with varying precision, so this lesson assigns no exact years.

Core beliefs: the Trinity, Christ, and salvation

Christians describe their central beliefs as flowing from Jesus. The mainstream creedal formulation of how the tradition understands God is the Trinity: one God as Father, Son, and Holy Spirit. OpenStax names the Holy Trinity, God, Jesus, Holy Spirit, as the Christian formulation, and Britannica records the Trinitarian invocation used in baptism. Christians identify Jesus as the Christ, the Messiah, and the Son of God; BBC Religions summarizes the belief that God sent his Son to save humanity from the consequences of its sins. Three further claims are central to the tradition's account of Jesus: the incarnation, the claim that God became human in Jesus; the crucifixion, his execution by the Roman authorities; and the resurrection, the claim that he rose from the dead. Britannica draws the same cluster together: Jesus Christ described as the incarnate Son of God whose life, death, and resurrection offer salvation. Salvation and grace are related themes: deliverance from sin, and the unearned favor through which, as the tradition teaches, salvation is received. This lesson presents all of these as claims of the tradition, never adjudicated.

Texts: the Bible

The sacred text of Christianity is the Bible, a collection in two parts. The Old Testament corresponds largely to the Hebrew Bible, the scriptures of Judaism, and is essential to Christianity; in Britannica's description it frames the tradition's understanding of God and human existence. The New Testament is the later collection written by and about the early movement: the Gospels, the accounts of Jesus' life and teaching, along with other early writings. BBC Religions states the structure plainly: the Christian holy book is the Bible, consisting of the Old and New Testaments. The Gospels depict Jesus, in Britannica's summary, as the definitive revelation of God, both teacher and savior. Churches translate, read, and interpret the Bible differently, but the two-part structure is shared across the tradition. Following this subject's convention, the lesson never quotes the Bible.

Practice: worship, sacraments, and the year

Christian practice centers on worship in churches, led by priests or ministers, as BBC Religions describes. Two rites are shared across nearly all Christian traditions: baptism, the rite of initiation using water, and the , also called Holy Communion or the Lord's Supper, the central act of worship in most churches, recalling Jesus' last meal with his followers. Catholic and Orthodox traditions count these among a larger set of sacraments; many Protestant traditions speak of ordinances. Prayer is a constant of Christian life, from personal prayer to structured liturgy. Many churches organize worship by a liturgical year, an annual cycle of seasons and holy days. The two great holidays are Christmas, the celebration of Jesus' birth, and Easter, which follows Lent and commemorates the resurrection; both have become milestones in many countries' secular calendars, as BBC Religions notes.

Diversity: churches, movements, and a global shift

Christianity is not one uniform church. The great families are the Roman Catholic Church, the Eastern Orthodox churches, and the Protestant churches. Britannica names the major branches as Roman Catholicism, Eastern Orthodoxy, Oriental Orthodoxy, and Protestantism, and the historical divisions are documented: the schism of 1054 divided the Western church, centered on Rome, from the Eastern churches, and the sixteenth-century Reformation produced churches that rejected certain Catholic teachings and structures. Within and beyond these families, movements such as Pentecostalism, Charismatic Christianity, and Evangelicalism are significant, along with numerous independent churches worldwide. The demographic center of Christianity has also moved. Pew Research's 2011 study Global Christianity counted 2.18 billion Christians, nearly a third of the global population, with more than 1.3 billion, about 61 percent, in the Global South. Sub-Saharan Africa's Christian share of its regional population rose from 9 percent in 1910 to 63 percent in 2010, while Europe's share of the world's Christians fell from about two-thirds in 1910 to about a quarter by 2010. Any accurate description of Christianity has to fit this diversity.

Christianity and culture

Christianity has generated a culture. Britannica puts it directly: the tradition is a faith and the culture that faith has created, with the church, the community of believers, as its agent. Christian themes and patronage have shaped painting, sculpture, architecture, and music for two millennia, and its teachings about love of neighbor and charity have shaped ethical traditions and institutions such as hospitals and schools. The influence shows in the calendar itself: Christmas and Easter are public holidays in countries worldwide, including many where Christians are a minority. Studying Christianity means studying a religious tradition and a cultural force at once, while keeping this lesson's descriptive stance: report, don't endorse or dismiss.

Eli, the EliExplains learning guide

Eli explains

The same idea, in plain words

Explain it like I’m 10

Start with one person. In the early first century CE, in the Roman-ruled land of Judaea, a Jewish teacher named Jesus gathered followers. Christians describe him as the Christ, the Messiah, and everything in the tradition circles around that claim. Their central beliefs are usually summarized as the Trinity, one God as Father, Son, and Holy Spirit, and as the incarnation, crucifixion, and resurrection: the claims that God became human in Jesus, that Jesus was executed, and that he rose again. The scholar's job is not to accept or reject these claims but to describe them accurately, and to describe the movement's diversity: Roman Catholic, Eastern Orthodox, and Protestant churches are the big branches, and newer movements such as Pentecostalism are growing quickly, especially in Africa, Asia, and Latin America.

Picture it like this

Picture a vast cathedral built by many hands over many centuries. The shared structure, the beliefs about Jesus, the Bible, baptism, and the Eucharist, is what holds it together, but inside, different chapels have different altars, music, and ways of praying: Catholic, Orthodox, and Protestant worship each has its own character. New movements keep adding chapels, and the congregation keeps changing.

Where the picture stops working

The analogy has limits. A cathedral has one roof, but Christianity has no single authority that all Christians answer to, and some divisions have been sharp. A cathedral is also fixed in stone, while Christianity keeps moving: its center of gravity has shifted from Europe toward Africa, Asia, and Latin America, which no building could capture.

Worked example

A student preparing a presentation is told to verify the claim that Christianity is a Western religion. She opens Pew Research's 2011 report Global Christianity and finds that more than 1.3 billion of the world's 2.18 billion Christians, about 61 percent, live in the Global South, and that sub-Saharan Africa's Christian share of its population rose from 9 percent in 1910 to 63 percent in 2010. She rewrites her opening line to say that Christianity, which began in the Middle East, is now a religion with most of its adherents in the Global South, and she cites the report's figures on her slide. The exercise teaches her to check demographic claims against documented data rather than inherited assumptions.

Key takeaway

Christianity is a diverse, global tradition centered on Jesus of Nazareth, best studied by describing what its churches and movements actually believe, practice, and document, never by assuming one uniform version.

Quick check

3 questions here, of 5 in this lesson’s practice set. Answers stay hidden until you check.

Question 1 of 3foundational

Which statement best describes the Trinity as the mainstream creedal formulation of Christianity?

Choose an answer, then check it.
Question 2 of 3foundational

How is the Christian Bible best described as a collection of texts?

Choose an answer, then check it.
Question 3 of 3intermediate

A student claims that Christianity is mainly a European religion today. Which finding from Pew Research best corrects that claim?

Choose an answer, then check it.
Practice all 5

Keep learning

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Practice this lesson
Study tools & related lessonsYou’ll learn to · Common mistakes · Easily confused · Key vocabulary · Related

You’ll learn to

  • Define Christianity as a diverse global tradition centered on Jesus of Nazareth, whom Christians identify as the Christ.
  • Describe the origins of the tradition in the early first century CE, in the historical framing scholars use.
  • Explain the Trinity as the mainstream creedal formulation and the incarnation, crucifixion, and resurrection as central claims of the tradition.
  • Distinguish the Old Testament, corresponding largely to the Hebrew Bible, from the New Testament, including the Gospels.
  • Describe Christian practice: worship, baptism and the Eucharist, prayer, the liturgical year, and the holidays of Christmas and Easter.
  • Analyze the diversity of Christian traditions, from the Catholic, Orthodox, and Protestant families to Pentecostalism and the documented growth of Christianity in the Global South.

Common mistakes

  • Treating Christianity as one uniform set of beliefs and practices.

    The tradition spans Roman Catholic, Eastern Orthodox, and Protestant churches plus movements such as Pentecostalism; describe the diversity rather than one generic version.

  • Asserting whether Christian claims, such as the Trinity or the resurrection, are true or false.

    This lesson presents them as central claims of the tradition; scholars describe them, they do not adjudicate them.

  • Equating the Old Testament with the Jewish Bible as if they were the same collection.

    The Old Testament corresponds largely to the Hebrew Bible but is a distinct Christian collection, arranged and interpreted differently.

  • Concluding that Christianity is in decline because attendance falls in parts of Europe.

    Pew Research documents global Christianity at 2.18 billion in 2010 with rapid growth in sub-Saharan Africa and Asia; European decline is one regional trend, not the whole picture.

Easily confused

Old Testament vs. New Testament

The Old Testament corresponds largely to the Hebrew Bible and frames God's dealings before Jesus; the New Testament is the later collection about Jesus and the early church, including the Gospels.

Baptism vs. Eucharist

Baptism is the rite of initiation, using water; the Eucharist (Holy Communion, the Lord's Supper) is the recurring central act of worship recalling Jesus' last meal with his followers.

Schism of 1054 vs. Protestant Reformation

The schism of 1054 divided the Western church from the Eastern Orthodox churches; the sixteenth-century Reformation produced the Protestant churches, which rejected certain Catholic teachings and structures.

Christmas vs. Easter

Christmas celebrates the birth of Jesus; Easter, which follows Lent, commemorates the resurrection and is the central holiday of the liturgical year.

Key vocabulary

Christ
A title from the Greek for anointed one, equivalent to the Hebrew messiah; Christians apply it to Jesus as the one promised in the Old Testament.
Trinity
The mainstream creedal formulation of one God as three persons: Father, Son, and Holy Spirit.
Incarnation
The claim, central to Christian teaching, that God became human in Jesus Christ.
Crucifixion
Execution by being fastened to a cross, a Roman method of capital punishment; Christians hold that Jesus was put to death this way in the early first century CE, in the early first century CE.
Resurrection
The claim that Jesus rose from the dead, which Christians hold as a central tenet of their faith.
Gospel
One of the four New Testament accounts of Jesus' life, teaching, death, and resurrection; the word means good news.
Sacrament
A sacred rite; baptism and the Eucharist are the rites most widely shared across Christian traditions, though churches number and name them differently.
Eucharist
The central act of worship in most Christian churches, also called Holy Communion or the Lord's Supper, recalling Jesus' last meal with his followers.
Old Testament
The first major part of the Christian Bible, corresponding largely to the Hebrew Bible of Judaism.
New Testament
The second major part of the Christian Bible: texts about Jesus and the early church, including the Gospels.

Sources & references

  1. 15.2 World Religions — Introduction to Sociology 3e — OpenStax, Rice University
  2. Christianity — Encyclopaedia Britannica
  3. BBC Religions — Christianity (at a glance and hub) — BBC Religions (British Broadcasting Corporation)
  4. Global Christianity – A Report on the Size and Distribution of the World's Christian Population (Executive Summary) — Pew Research Center

EliExplains lessons are original prose written from the open, credible references above. See Copyright & Licensing.

Researched 2026-08-21

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