The First 1,000 Years of Christianity: A Journey Through History

Christianity began over 2,000 years ago, but the first 1,000 years were some of the most important in shaping what it has become today. From a small group of followers to a global religion, the story of early Christianity is full of courage, growth, struggle, and transformation.

Let’s take a journey through the first millennium of Christianity—broken down into key events and easy-to-understand moments that tell the story of how the Christian faith spread and changed the world.

1. The Life and Teachings of Jesus (Around 4 B.C. – 30 A.D.)

Christianity begins with Jesus of Nazareth, who was born in Bethlehem and lived in the region of Judea (modern-day Israel/Palestine). Christians believe Jesus is the Son of God and the Messiah (or “Christ”) promised in Jewish scriptures.

Jesus taught about love, forgiveness, truth, and God’s Kingdom. He performed miracles, healed people, and challenged religious leaders of His day. Around age 33, He was crucified by the Romans, died, and—according to Christian belief—rose from the dead three days later. This event, called the Resurrection, is considered the foundation of Christian faith.

2. The Early Church and the Apostles (30–100 A.D.)

After Jesus’ resurrection, His followers, known as apostles, began to share His message. The most well-known apostles include Peter, James, John, and Paul (who once persecuted Christians before becoming one himself).

The apostles traveled far and wide—especially Paul—spreading the gospel across the Roman Empire. They started small communities (churches) and wrote letters to encourage and teach them. Some of these letters later became part of the New Testament in the Bible.

Christians were often persecuted by Roman authorities during this time. Many were arrested or even killed for their beliefs, including Peter and Paul, who both died in Rome.

3. Christianity Spreads and Faces Persecution (100–313 A.D.)

Despite persecution, Christianity grew quickly. Christians were known for helping the poor, caring for the sick, and living differently than others around them. They worshiped one God in a world where most people worshiped many gods.

During this time, Roman emperors often blamed Christians for problems in society. Many believers were thrown into prison, tortured, or killed in arenas as public entertainment. These people are known as Christian martyrs, and their bravery inspired many.

Still, the Christian message kept spreading—to North Africa, Europe, the Middle East, and beyond.

4. The Conversion of Constantine (313 A.D.)

A major turning point happened in 313 A.D. when the Roman Emperor Constantine became a Christian (or at least supported Christianity) after claiming to see a vision of a cross in the sky before a battle. He issued the Edict of Milan, which made Christianity legal in the Roman Empire.

This changed everything.

Now Christians could worship freely. Churches were built. Bishops became respected leaders. Eventually, Christianity became the official religion of the Roman Empire.

Constantine also called the Council of Nicaea in 325 A.D., where church leaders came together to agree on core beliefs—like the Trinity (God as Father, Son, and Holy Spirit). This was the beginning of church councils, where important decisions were made about Christian teachings.

5. The Rise of Church Leaders and Structure (300–500 A.D.)

As Christianity became more organized, leaders called bishops oversaw churches in different regions. The Bishop of Rome (who later became known as the Pope) became especially important, especially as the western part of the Roman Empire declined.

The Bible was being carefully put together during this time. The Old Testament (Hebrew Scriptures) and the New Testament (Gospels, letters, and other writings about Jesus) were being officially recognized as Holy Scripture.

Also during this period, some Christians chose to live simple lives devoted to prayer. These people became monks and nuns, and they started monasteries—places to live, study, and worship. Monasteries later became important centers of education and charity.

6. The Fall of the Western Roman Empire (476 A.D.)

In 476 A.D., the Western Roman Empire collapsed due to attacks by barbarian tribes (like the Visigoths and Vandals). This caused chaos in Europe.

But Christianity didn’t collapse. Instead, the Church became a source of stability. Popes, bishops, and monks helped keep communities together, protected people, and kept learning alive.

During this time, missionaries were sent to new lands. For example:

• St. Patrick brought Christianity to Ireland.

• St. Augustine of Canterbury brought the faith to England.

• St. Boniface preached to the Germans.

7. The Rise of the Byzantine Empire and the Eastern Church (500–800 A.D.)

While the western part of the Roman Empire fell apart, the Eastern Roman Empire (also called the Byzantine Empire) continued for hundreds of years. Its capital was Constantinople (modern-day Istanbul).

The Eastern Church, known later as the Eastern Orthodox Church, developed its own customs, traditions, and leadership, separate from the Western Church led by the Pope.

The two sides still shared the same core beliefs in Jesus, the Bible, and the sacraments—but over time, differences in language, culture, and leadership caused tensions.

8. Charlemagne and the Holy Roman Empire (800 A.D.)

In 800 A.D., the Pope crowned a powerful ruler named Charlemagne as Emperor of the Holy Roman Empire. This was a big deal because it showed that the Church and government were closely linked.

Charlemagne encouraged learning and the copying of the Bible. He supported monasteries and helped spread Christianity through Europe. His rule is sometimes called the Carolingian Renaissance because it helped renew interest in learning and faith.

9. The Great Schism Begins to Take Shape (900–1000 A.D.)

By the end of the first millennium, tensions between the Roman Catholic Church (based in Rome) and the Eastern Orthodox Church (based in Constantinople) were growing stronger.

Reasons for conflict included:

• Disagreements about who had more power—the Pope or the Patriarch of Constantinople.

• Differences in worship styles and traditions.

• Arguments over small theological issues, like whether the Holy Spirit comes from the Father only or from the Father and the Son.

Although the official split (The Great Schism) wouldn’t happen until 1054 A.D., the foundations of division were already forming during this time.

10. Christianity at 1,000 Years: A Global Faith

By the year 1000 A.D., Christianity had:

• Spread across Europe, parts of Africa, and into Asia.

• Become a major force in both religion and politics.

• Split into two large cultural and spiritual families: the Western Church (Roman Catholic) and the Eastern Church (Orthodox).

It had survived persecution, political upheaval, and cultural change. The Bible was being preserved and taught in monasteries. New leaders were emerging. And ordinary people were being shaped by the teachings of Jesus in daily life.

🕊️ Final Thoughts: Why the First 1,000 Years Matter

The first 1,000 years of Christianity laid the foundation for everything that came after. It showed that faith could survive—and even thrive—in times of peace and war, freedom and persecution, unity and division.

It also reminds us that the Church is more than buildings or leaders—it’s a global community of people who believe in the message of hope, grace, and love that Jesus taught.

Understanding this early history helps us appreciate how Christianity became the world’s largest religion and continues to impact lives around the globe.