History of Christianity

The history of Christianity follows the Christian religion from the first century to the twenty-first as it developed from its earliest beliefs and practices, spread geographically, and changed into its contemporary global forms.

Christianity originated with the ministry of Jesus, a Jewish teacher and healer who proclaimed the imminent Kingdom of God and was crucified c. AD 30–33 in Jerusalem in the Roman province of Judea. The earliest followers of Jesus were apocalyptic Jewish Christians. Christianity remained a Jewish sect, for centuries in some locations, diverging gradually from Judaism over doctrinal, social and historical differences.

In spite of occasional persecution in the Roman Empire, the religious movement spread as a grassroots movement that became established by the third century both in and outside the empire. New Testament texts were written, and church government was loosely organized, in its first centuries, though the biblical canon did not become official until 382. The Roman Emperor Constantine I became the first Christian emperor in 313. He issued the Edict of Milan, expressing tolerance for all religions and thereby legalizing Christian worship. He did not make Christianity the state religion, but did provide crucial support. Constantine called the first of seven ecumenical councils needed to resolve disagreements over defining Jesus' divinity.

Christianity played a prominent role in the development of Western civilization in Europe. In the Early Middle Ages, missionary activities spread Christianity west and north. During the High Middle Ages, Eastern and Western Christianity grew apart, leading to the East–West Schism of 1054. Western Christianity reached a kind of peak, influencing every aspect of medieval life in the 1200s, then it began a decline. Growing criticism of the Roman Catholic church and its corruption in the 1300–1500s led to the Protestant Reformation and its related reform movements, which concluded with the European wars of religion, the return of tolerance as a theological and political option, and the Age of Enlightenment. Christianity also heavily influenced the New World through its connection to colonialism, its part in the American revolution, the dissolution of slavery in the west, and the long term impact of Protestant missions.

In the twenty-first century, traditional Christianity has declined in the West, while new forms have developed and expanded throughout the world. Today, there are more than two billion Christians worldwide and Christianity has become the world's largest, and most widespread religion. Within the last century, the center of growth has shifted from West to East and from the North to the global South.