Historians often ask themselves just what caused the first disciples to believe, after Jesus’ crucifixion, that he was now alive as their exalted and glorified Lord.
My own theory (which is hardly original) starts from the earliest account that we have of an ‘appearance’ of the risen Lord, that of Paul on the Damascus road about two or three years after the crucifixion. Paul, as reported in Acts 9:3-8 (repeated in 22.6-11 and 26:12-18), experienced a blinding light and heard (inwardly, according to one of the accounts) a voice but did not see any bodily presence; if he had, this would also have been seen by the others present. Paul himself equated this experience with the paradigm ‘appearances’ to Peter and the twelve (see 1 Corinthians 15:8). Barnabas likewise described the Damascus road experience as Paul’s ‘seeing of Jesus’ (Acts 9:27).
Howard Kee commentating on Paul’s reference in 1 Corinthians 15:8 to his Damascus road experience says:
‘Paul makes no distinction between his having seen Jesus and the appearances of Jesus to the disciples. Equally important is that apparently they also saw no difference between Paul’s experience and theirs, since they accepted him as having been called to apostleship by the risen Christ, just as they had been.’
Howard Kee, What Can We Know About Jesus? p. 1. (Kee was Professor of Biblical Studies at Boston University School of Theology).
It seems reasonable to conjecture that the original resurrection event consisted of Peter, perhaps others of the twelve and some of the women having an experience essentially similar to that of Paul: an experience of a supernatural light around them within which they were conscious of the glorified Jesus. Near death experiences often report something rather like this in the form of a bright light, or a brightly shining figure, from which comes a deeply accepting love and peace. Christians who have had this experience usually identify the being of light with Christ. The original resurrection ‘appearances’ may quite possibly have been waking versions of this same type of experience.
On this hypothesis the stories of the empty tomb (Mark 16:5), the zombie apocalypse (Matt 27:52-53), etc., are all later elaborations as the story developed through the decades.