This book gives a five-part definition of the Resurrection of Jesus, which I always thought was just the renewed fellowship of his followers after his execution. According to The First Christmas: What the Gospels Really Teach About Jesus's Birth by John Dominic Crossan and Marcus Borg, the resurrection occurred within a few years the crucifixion. The author of this book agrees with the timing in the Gospels, and calls the Resurrection a "puzzle" because he is trying explain the Resurrection by analyzing the Gospels in light of the Shroud of Turin. Concerning the blood and body images of the Shroud of Turin,
The two superimposed images are in perfect accord; they reinforce each other, proving beyond doubt that the Shroud really did enfold the dead body of a crucified man. The question is: who was the man, and how did his body leave an eerie stain on its winding sheet? (location 3012)
The author says, "When faced with a mysterious phenomenon, it is generally wise to presume that it has a natural cause." (location 3096) When the mysterious phenomenon is an image, it is generally wise to presume an artist created it. The author does not do this. He presumes that the Shroud of Turin is authentic, and that no artist or artisan was involved in its creation.
This is the author's definition of the Resurrection:
The first and most obvious puzzle associated with Christianity is that its founders, the former followers of Jesus, were inspired by his crucifixion.…A second puzzle is that, following his death, the Nazarenes hailed Jesus as the Messiah, the anointed leader of the Jewish nation.…A third peculiar aspect of Christianity was it obsession with, and development of, the Jewish notion of resurrection.…Fourthly, there is the remarkable fact that the Nazarenes adopted Sunday, the first day of the week, as a new day of worship, compromising the unique importance of the Sabbath.…This—the fifth and greatest puzzle concerning the Nazarenes—is the relatively short-term question: how did the apostles manage to create a church in the first place, an assembly that had the capacity to grow?" (extracted from 1340 to 1448)
To this list I would add the puzzle of who created the Shroud of Turin and how was it created.