But some historians think there was no physical resurrection. They believe the resurrection stories were made up and written decades after Jesus' death.
They say after the crucifixion, the disciples -- dispirited and defeated -- simply went home to their lives as fishermen on the Sea of Galilee. Instead of a physical return of Jesus, they say, the stories in the Gospels are describing dreams or visions that Jesus' closest followers had.
"The kind of resurrection body that the Gospels talk about -- the Gospel of John, for example, where Jesus appears in a room with locked doors is not physical in our understanding of the body. Those kinds of experiences suggest not the kind of physical body that we would see today. But something that we -- if we have to use our categories would look much more like a visionary experience," said Karen King of the Harvard Divinity School.
Scholars also say that dreams to people in the first century were no less real than waking reality. "In the ancient world, dreams were real. If you had a dream at night, the assumption was that it was real," said Arthur Dewey of Xavier University in Cincinnati, Ohio.
The University of Wisconsin's Corley thinks the disciples visions of Jesus grew from their extraordinary grief. "I talked about grief experiences. It's been documented in modern times that people in times of extreme mourning and bereavement will see -- actually see -- honestly believe they see the dead person before them," she said.
Baumgarten agrees. "People whose hopes have been dashed in that awful way very often come up with various items of belief," he said.
While these scholars don't believe there was a physical resurrection, they agree that something extraordinary occurred.
Shelby Spong, like many other Christians, believes the Resurrection was a spiritual event. "I think it's real. I think it took place in Galilee. I think Peter stood in the center of it. I think it has something to do with the breaking of bread. He was made known to us in the breaking of the bread. I don't know exactly what that is. But it is clear to me that there was something that opened their eyes to see a dimension of reality that I believe is beyond the boundaries of normal," he said.