Events that seem to defy scientific or commonsense explanation have been part of Christian tradition since biblical times. The Gospel of John refers to seven such marvels as signs of God’s power and glory as manifested in Jesus. Beginning with his changing water into wine at the wedding feast at Cana (John 2:1-11) and ending with the raising of Lazarus from the dead (John 11), the fourth Gospel emphasizes the connection between faith and the recognition of signs. At the end of his work the evangelist refers to Jesus’ post-resurrection appearances as signs as well, and says that Jesus worked many others not recorded in his Gospel, all so that people might believe in the name of Jesus Christ (John 20:30-31).

The other Gospels likewise use the language of signs so as to underscore two important aspects of miracles. First, miracles are in the mind of the believer. On numerous occasions Jesus performs a deed before large crowds. Some see the deed and believe; others see it and ask Jesus when he will work a “real” sign. Second, in the absence of faith on the part of those present, Jesus cannot or chooses not to effect his wondrous actions (Mark 6:5-6). In other words, miracles are not merely a gimmick for changing people’s minds. Post-biblical Christian tradition has attributed numerous miraculous deeds to the mediation of holy persons as well as to direct divine intervention. Most common are reports of healings and apparitions, but accounts of paranormal events such as levitation or bleeding wounds on hands and feet (known as stigmata) are also well known.