Christianity

About 2.3 billion people, nearly three in ten on Earth, are Christians: Catholics, Protestants, Orthodox and many others.

Christians believe that Jesus of Nazareth is the Son of God, who died for the sins of the world and rose from the dead. Historians, whatever their beliefs, study him as a Jewish preacher of the 1st century whose life can be reconstructed from early sources.

This episode follows both stories.

Judea and Galilee were under Roman power, through client kings like Herod and Roman governors. Taxes were heavy, and many peasants lived in debt.

Jews longed for God to act: to free Israel, restore justice and bring in God’s kingdom. Some expected a messiah, an anointed king. Prophets and rebels appeared, and Rome crushed them.

Jesus grew up in Nazareth, a small village in Galilee, probably working as a builder or carpenter. Like other Jews of his time, he followed the Torah and went to Jerusalem for the festivals.

After being baptised by the prophet John the Baptist, Jesus began preaching in Galilee that the kingdom of God was near. He taught in parables, healed the sick, and ate with outcasts and sinners.

He taught love of God and neighbour, even of enemies, and blessed the poor. He gathered twelve close disciples.

Around AD 30 he came to Jerusalem at Passover. After a disturbance in the Temple he was arrested and crucified by order of the Roman governor Pontius Pilate, a punishment for rebels and slaves.

His followers soon proclaimed that God had raised him from the dead on the third day, and that he was the Messiah, the Christ. This belief is the foundation of Christianity.

At first, Jesus’ followers were a movement within Judaism, led in Jerusalem by Peter and James, Jesus’ brother.

Paul, a Pharisee who had persecuted them, had a vision of the risen Jesus around AD 34. He became the great missionary to non-Jews, founding communities across Asia Minor and Greece.

Around AD 49 the leaders agreed that non-Jewish believers did not need to be circumcised or follow the whole Torah. Over the following decades Christianity gradually separated from Judaism.

Paul’s letters, from about AD 50 to 60, are the oldest Christian writings. The four Gospels were written later, between about 65 and 100.

Christians refused to honour the Roman gods or the emperor, which made them suspect. In AD 64, Nero blamed them for the great fire of Rome.

Persecution came in waves, worst under Decius in 250 and in Diocletian’s Great Persecution from 303. Martyrs who died for their faith were honoured as saints.

Yet the church kept growing, through care for the poor and sick, strong communities and conversions, especially in cities. By 300 perhaps one in ten people in the empire were Christians; estimates vary.

In 312 the emperor Constantine fought under a Christian sign at the Milvian Bridge and won. In 313 Christianity was legalised.

Constantine called the Council of Nicaea in 325 to settle disputes about the nature of Christ. It produced the Nicene Creed, still recited by most churches.

In 380 Christianity became the official religion of the empire. By the late 4th century the 27 books of the New Testament were widely accepted.

Christianity was never only a European religion. Armenia adopted it as a state religion, by tradition in 301, and the Ethiopian kingdom of Aksum under King Ezana in the 330s.

The Church of the East spread through Persia and Central Asia. Christians in Kerala, India, trace their church to the apostle Thomas.

In 635 a missionary named Alopen reached the Tang capital Chang’an; a stone monument erected in 781 records the “Luminous Religion” in China.

Monasteries, like Benedict’s at Monte Cassino around 529, preserved learning and carried the faith across Europe. Kyiv’s prince was baptised in 988, bringing Orthodox Christianity to the Rus.

The Latin West, led by the pope in Rome, and the Greek East, centred on Constantinople, drifted apart. A mutual excommunication in 1054 is taken as the start of the Catholic–Orthodox split.

From 1095 popes called crusades to take Jerusalem from Muslim rule. They brought great violence, against Muslims, Jews and Eastern Christians, and ended with the loss of the last crusader city in 1291.

In 1517 the German monk Martin Luther challenged the sale of indulgences. He taught that people are saved by faith alone, and that scripture, not the pope, is the final authority.

The printing press spread his ideas and Bibles in everyday languages. Protestant churches, Lutheran, Reformed, Anglican and others, broke away from Rome.

The Catholic Church answered with its own reforms. Wars of religion devastated Europe until the Peace of Westphalia in 1648.

Spanish and Portuguese empires brought Catholicism to the Americas and the Philippines, often through forced conversion alongside conquest. Some missionaries, like Bartolomé de las Casas, protested the cruelty.

Jesuits travelled to India, Japan and China, adapting to local cultures. Francis Xavier reached Japan in 1549.

Catholic missionaries arrived in Ayutthaya in 1567, and French missions came under King Narai. Today about one percent of Thais are Christian.

In the 20th century, Christianity grew fastest in Africa, Latin America and parts of Asia, while church attendance fell across much of Europe.

Today more Christians live in sub-Saharan Africa than in Europe. Pentecostal and charismatic churches are among the fastest-growing.

The largest single church is the Roman Catholic Church, with over a billion members.

Christianity began as a Jewish hope for God’s kingdom, became the faith of Rome, divided into many churches, and spread to every continent.

Next: Islam, which rose in Arabia six centuries later, honouring Abraham, Moses and Jesus as prophets.