World Religions › Classical faiths
Christianity
c. AD 30 – today; about 2.3 billion followers· Religion or tradition· Judaism, Christianity & Islam
Historical recordConfirmed by archaeology, outside sources or contemporary records.
The faith centered on Jesus, whom Christians believe is the Son of God who died and rose to save humanity; the world's largest religion.
See it on the World Religions map →What it is
Christians believe in one God in three persons, Father, Son and Holy Spirit, and that salvation comes through Jesus' death and resurrection. The faith began around AD 30 as a Jewish movement in Judea, spread through the Roman Empire despite persecution, and became Rome's state religion in 380. Its main branches are Catholic (about half of all Christians), Protestant and Orthodox. With about 2.3 billion followers, nearly 3 in 10 people, it now has more adherents in sub-Saharan Africa than in any other region.
Why it matters
It shaped Western law, art, calendars, universities and hospitals, and through missions and empire spread to every continent; its growth now lies mostly in the global South.
Sources and history
Roman writers such as Tacitus and Pliny the Younger (c. 112) describe early Christians; early manuscripts, catacombs and the house church at Dura-Europos (c. 240); modern censuses and Pew Research surveys.
Questions and debates
How a movement of perhaps under 10,000 people in AD 100 grew to several million by 300 is still debated; all such numbers are estimates.
Inside this (6)
Connections (4)
▸Jesus of Nazareth is the central figure of ChristianityHistorical record
The connection
Christianity takes its name from Christ, Greek for 'Messiah' or 'anointed one', the title his followers gave Jesus. Its worship, creeds and calendar center on his life, death and resurrection. Christians believe he is God incarnate, the Son within the Trinity, and that following him brings salvation.
When and where
Judea and Galilee, c. AD 30, spreading to Antioch in Syria, where, Acts says, followers were first called 'Christians' within a decade or two.
Historical evidence
The New Testament, early Christian writings and Roman sources such as Pliny (c. 112), who reports Christians singing hymns 'to Christ as to a god'.
Questions and debates
Historians debate how quickly followers came to worship Jesus as divine; many now argue it began very early, within a few years of his death.
▸Christianity grew out of Second Temple JudaismHistorical record
The connection
Christianity began as a Jewish movement: Jesus and his first followers were Jews who worshipped at the Temple and drew on Jewish scripture, messianic hopes and belief in resurrection. As Gentiles joined without adopting Jewish law, and after the Temple fell, the two communities gradually separated into distinct religions.
When and where
Judea, Galilee and the Jewish diaspora, c. AD 30–135; Jerusalem's church was led by James, Jesus' brother, until his death in 62.
Historical evidence
The New Testament's Jewish setting and scripture; Josephus mentions James' execution; the Dead Sea Scrolls show Jewish ideas, like a coming Messiah, that Christians shared.
Questions and debates
When the 'parting of the ways' was complete is debated: estimates range from AD 70 to the 300s or later in some places.
▸Constantine, the first Christian emperor legalized and favored ChristianityHistorical record
The connection
Constantine ended persecution in his lands, and the Edict of Milan (313) guaranteed Christians freedom of worship and returned their property. He then gave clergy tax exemptions, let bishops judge legal cases, built major churches and made Sunday a day of rest in 321. Under such patronage the church grew rapidly in the following decades.
When and where
Rome, Milan and Constantinople, 312–337. Emperor Galerius had already issued an edict of toleration in 311; Constantine became sole emperor in 324.
Historical evidence
Laws preserved in the Theodosian Code, Lactantius' text of the Milan agreement, Eusebius' writings, and surviving churches such as the Lateran in Rome.
Questions and debates
How much growth came from imperial favor rather than earlier momentum is debated; Christians were perhaps a tenth of the empire's people in 312, an estimate.
▸Great Schism between East and West divided ChristianityHistorical record
The connection
Long-growing differences between the Latin West, led by the pope in Rome, and the Greek East, centered on Constantinople, split Christianity in two. They disputed the pope's authority, the Creed's 'filioque' phrase about the Holy Spirit, and practices such as leavened bread. The resulting Catholic and Eastern Orthodox churches remain separate today.
When and where
Constantinople, 1054: papal legates and Patriarch Michael Cerularius excommunicated each other. The Crusaders' sack of Constantinople in 1204 deepened the break.
Historical evidence
The excommunication documents survive; Pope Paul VI and Patriarch Athenagoras formally lifted the mutual excommunications in 1965.
Questions and debates
Historians debate whether 1054 marks the real split or one episode in a separation that unfolded over centuries; reunion talks continue.