Christianity’s origins can be traced back to the 1st century AD and stem from the life, teachings, and death of Jesus of Nazareth (the Christ). It is one of the largest religions in the world and probably the most widely diffused geographically. It has more than two billion believers worldwide, and the Roman Catholic Church, the Protestant churches, and the Eastern Orthodox churches are the largest groups.

After the death of Jesus Christ, Christianity first emerged as a Judaism sect, practiced in Judea, the Roman province. A Christian mission is an organized effort in the propagation of the Christian faith. The earliest missions were the Great Commission and Dispersion of the Apostles.

Let’s take a look at how Christianity spread through history.

Missionary activity

Christian missionary activity was mainly responsible for the spread of Christianity and helped spread it from the Eastern Mediterranean throughout the Roman empire and beyond. After the death of Jesus, His followers extended their outreach to all of Israel. Within ten years of His death, Christianity had spread from Jerusalem to Rome, Alexandria, Crete, Cyprus, Thessalonica, Corinth, Ephesus, and Antioch.

Ante-Nicene period (2nd-3rd century)

Roman Empire

Beyond the Roman Empire, Christianity also spread to the Parthian Empire and the Sasanian Empire, including Mesopotamia. The Kingdom of Armenia was the first state to declare Christianity as its state religion in 301 AD.

Christianity had spread throughout Persia, Media, Bactria, and Parthia by the latter half of the 2nd century.

Many of the early Christians were merchants who traveled to places like Africa, Asia, Greece, Arabia, and other places for trade and other purposes. By the year 100 AD, 40 Christian communities were established. Towards the end of the 1st century, Christianity had already spread to Rome, Armenia, Syria, and Greece, which laid the foundation for the spread of Christianity throughout the world.

Late antiquity (313-476 AD)

Emperor Constantine I and Emperor Licinius issued the Edict of Milan that legalized Christian worship in 313 AD. The Roman Empire officially adopted Christianity as its state religion in February 380 AD.

However, Christianity was not confined to the Roman Empire during late antiquity. Christianity in ancient Iberia (present-day Georgia) dates back to the 4th century. Mirian III, the Iberian King, converted to Christianity in 326 AD.

According to 4th-century historian Tyrannius Rufinus, Christian missionary Frumentius brought Christianity to Ethiopia and also served as its first bishop in 325 AD.

After the fall of the Western Roman Empire in 476 AD, the Catholic Church competed with Arian Christians for the conversion of the barbaric tribes. Catholicism quickly became the dominant form of Christianity and spread throughout Europe to the English, Irish, Goths, and Franks.

Age of Discovery

Christianity expanded throughout the world during the Age of Discovery, also known as the Age of Exploration, resulting in it becoming the largest religion in the world.

The Age of Exploration that lasted between the 15th century and the late 18th century was a period in European history with extensive overseas exploration. Led by the Portuguese, it led to the rediscovery of the Americas by the Europeans. The period also marked the increased adoption of colonialism as a national policy of Europe.

Explorations went beyond the Mediterranean after the Portuguese discovered Madeira in 1419 and Azores in 1427 AD. The coast of West Africa was discovered in 1434, and Vasco Da Gama established the sea route to India in 1498 AD. Spain sponsored the voyages of Christopher Columbus to the Americas between 1492 and 1504 AD. Ferdinand Magellan began the circumnavigation of the globe between 1519 and 1522 AD.

These discoveries led to several land and naval expeditions to the Americas, Asia, Australia, and Africa across the Atlantic, Pacific, and Indian oceans that continued well into the late 19th century.

20th century

By the 20th century, Christianity had spread to the non-Western regions of the world. It became the most widely disseminated religion in the world. There were virtually no countries left in the world unaffected by Christian missionaries. However, in many countries of the world, Christians account for only a minor part of the population. Many countries in Asia and Africa, including India and China, have Christian minorities.

Why did Christianity spread so rapidly?

In Rodney Stark’s The Rise of Christianity, he argues that Christianity replaced paganism mainly because it enriched the lives of its followers in various ways.

According to Bart D. Ehrman, the spread of Christianity was rapid because of five factors:

  1. Christianity promised salvation and eternal life for everyone, which was an attractive alternative to Roman religions.
  2. Stories of miracles and healing by Jesus Christ allegedly showed that one Christian God was perhaps more powerful than the many Roman gods.
  3. Christianity worked at the grass-root level providing hope of a better future in the next life for the lower classes.
  4. Christianity took worshipers away from other religions. Those who converted to Christianity were expected to give up the worship of other gods, which was unusual in the ancient past, where the worship of multiple Gods was common.
  5. In the Roman empire, if you converted one person to Christianity, it often meant that the whole household got converted. If the head of the household was converted, he decided the religion of his wife, children, and slaves, which lead to an increase of Christian followers.
  6. Inside the conversion tactics of the early Christian church
  7. Why did Christianity succeed?


Christianity is the most widely practiced religion in the world, with over two billion followers globally. Though it started with a relatively small group of adherents, it has now spread across the world. Almost all countries in the world have at least a fraction of their population following Christianity. Many historians regard the spread and adoption of the Christian faith across all countries of the world as one of the most successful spiritual missions on earth.