On the evening of the day Jesus was crucified, his disciples were hiding behind locked doors, paralysed by fear (John 20:19). Within fifty days, they were proclaiming his resurrection before thousands in the streets of Jerusalem (Acts 2:41). Within a generation, the message had spread across the Roman Empire. Within three centuries — often under fierce persecution — Christianity had become the dominant religion of the Mediterranean world. How do we account for this extraordinary transformation?

There is no adequate explanation that does not include the resurrection of Jesus. The resurrection is not one element in the story of Christianity’s rise — it is the entire engine of it. Remove the resurrection, and you do not have a diminished Christianity. You have no Christianity at all.

A Message Without a Messenger

Consider what the disciples had before the resurrection. They had a beloved teacher who had been publicly humiliated and executed as a criminal. They had shattered hopes. They had the memory of their own betrayal and cowardice. Without resurrection, this is a story of failure, not a foundation for a world movement. As Paul wrote with brutal clarity: “if Christ has not been raised, your faith is futile and you are still in your sins” (1 Cor 15:17). The early Christians understood perfectly that their entire message stood or fell on whether Jesus was actually alive.

And they preached this message not in a distant location, safely removed from the evidence, but in Jerusalem itself — the city where Jesus had been killed, within easy reach of the sealed tomb, in the immediate aftermath of the crucifixion. If the body had still been in the tomb, the authorities could have ended the movement in an afternoon. They did not. The body was not there.

From Fearful to Fearless

The transformation of the disciples is one of the most historically dramatic facts connected with the resurrection. Before the crucifixion, when Jesus was arrested, his disciples “all left him and fled” (Mark 14:50). Peter, the leader among them, denied knowing Jesus three times under the mild pressure of bystanders (Mark 14:66–71). These were not men of extraordinary courage.

Within weeks, these same men were standing before the very authorities who had crucified Jesus and declaring that God had raised him from the dead (Acts 4:1–13). Peter preached with such boldness that the Jerusalem authorities were astonished and could “see that they were unschooled, ordinary men” (Acts 4:13). Something had happened to them. Something so radical and so certain that it lifted their vision, revived their courage, and sent them to the ends of the earth.

What was the cause of this transformation? The resurrection appearances of Jesus are the only historically adequate explanation. The disciples did not slowly convince themselves that Jesus must have risen. They encountered him. That encounter converted bewilderment into certainty, and certainty drove everything that followed.

The Historian Josephus and the Spread of the Faith

The significance of Christianity’s rise was noted not only by its adherents but by its critics. The Jewish historian Flavius Josephus (AD 37 – c. 100) — writing without any Christian agenda — recorded that Jesus appeared to his disciples after being crucified and restored to life.¹ That an ancient Jewish historian, operating in a context hostile to Christianity, felt compelled to record this tradition is remarkable testimony to how widely and firmly the resurrection claim had taken hold.

The spread of Christianity across the first three centuries, often in the face of severe and organised persecution, is most readily accounted for by the resurrection being well-founded in fact. The Gospels directly indicate that Jesus’ resurrection is a divine necessity (Luke 24:46, John 10:17-18). Developing this, the Acts of the Apostles and the epistles stress that God, his divine purpose and power, is why the resurrection of Jesus, and what followed, has happened (Acts 2:22-24; Rom 6:4-5, 8:11). This resurrection power reaches into the very depths of the being of Christian believers, changes them and the world around them as the gospel is proclaimed (Acts 2:37-41, 19:23-27; 1 Thess 1:5-9). In that way, the resurrection of Jesus explains the content and focus of the Gospels, apostolic letters, the liturgical practices, the martyrdoms, and the remarkable vitality of a movement that no human power could extinguish. It was and is God himself acting.² “The actual historical effect is inconceivable without the resurrection of Jesus as its objective historical cause.”³

1. Josephus, Jewish Antiquities, 18.3.63–64. This part of the present manuscript is widely perceived by scholars to have been subject to a 4th or 5th century insertion or re-writing of an original text that may have stated that this was an event the disciples believed had happened, i.e., Josephus is not endorsing it at as true, per se, but reporting the apostles’ belief. ↩︎
2. Arguably, the Gospels implicate God as the actor in the resurrection, by using the passive voice ēgerthē “he was raised,” Matthew 28:5-6; and by Jesus himself depicting his coming death and resurrection as a divine necessity, Luke 24:46. ↩︎
3. Oden, Systematic Theology, 2:491. ↩︎