A Eucharistic miracle is an allege miracle when, during consecration during the Catholic Mass, the bread and wine visibly become the body and blood of Jesus Christ. Catholics believe that when the priest pronounces the words of consecration, the bread and wine actually become the body and blood of Christ, but retain the outward appearance of bread and wine. This is called transubstantiation, and differs from most Protestant Eucharistic theologies, which believe that the sacramental elements are not physically transubstantiated. Some Catholics claim that Eucharistic miracles happen most often when people, mainly priests or monks, doubt the Real Presence of Christ in the Eucharist.