Anders,
I read your link on mass hysteria/hallucinations. This has been suggested before as a possible explanation and is a skeptic favorite. There are some pretty big absurdities with this explanation:
Such hallucinations, if this is what they were, are quite unique and should warrant careful psychological scrutiny. These [supposed hallucinations of the disciples] were experienced by a considerable number of different individuals, all seeing the same vision, but in different groups, at different times, both indoors and outdoors, on a hilltop, along a roadway, by a lakeshore, and other places. Furthermore, they were not looking for Jesus at all. Several times they didn't recognize Him at first, and at least once actually believed it was a ghost until He convinced them otherwise. He invited them to touch Him and they recognized the wounds in His hands (John 20:27; Luke 24:39). They watched Him eat with them (Luke 24:41–43). On one occasion, over 500 different people saw Him at one time (1 Corinthians 15:6), most of whom were still living at the time when the evidence was being used.5
Still more problems exist for this popular skeptical view. How does one explain the appearance of Jesus to Paul on the road to Damascus? Surely Paul was not grieving over the death of Jesus. He was zealously persecuting followers of Christ and “still breathing threats and murder against the disciples” (Acts 9:1). He was not in any state of mind to experience a hallucination of Jesus, particularly one that would transform his life so drastically. Yet Paul’s experience is one of the five key evidences, meaning it is well-evidenced and accepted by the vast majority of scholars on the subject.
Also among the key evidences are the empty tomb and the conversion of James due to a purported post-Resurrection appearance of Jesus. The mass hallucination theory cannot account for the empty tomb .
Nor can the hallucination view make sense of the conversion of James. While James may have grieved the loss of his half-brother, the death of Jesus would have confirmed his skeptical view of the Lord’s claim to be the Savior. Only upon seeing the risen Lord did James come to believe in Jesus as the Jewish Messiah.6
I think that if a defeated, disillusioned & ragtag group of disciples could pretty much overnight be transferred into a dedicated & energetic faith movement through mass hysteria, self-deception, & dedication to living and dying for a KNOWN LIE; then that would be a greater miracle than the resurrection itself.
Hume argued that the wise man “proportions his belief to the evidence,”8 so he thought the evidence would always favor a naturalistic explanation over a supernatural one. Yet in this case, it would be a far greater miracle for entire groups of people in different mental states to undergo shared hallucinations on different occasions, in different places, and for different reasons.9
I guess we all choose the miracles we believe in. For many, the resurrection is the more believable.