Most New Testament critics today admit Jesus performed what we would call miracles. Granted, they may not all believe these were genuine miracles, but the idea of Jesus of Nazareth as a miracle worker and exorcist is part of the historical Jesus that’s generally accepted by critics today.
Rudolf Bultmann, who is recognized as one of the most skeptical New Testament critics of the last century, wrote:
The Christian fellowship was convinced that Jesus had done miracles and they told many stories of miracles about him. Most of these stories contained in the Gospels are legendary or are at least dressed up with legend. But, there can be no doubt that Jesus did such deeds, which were, in his and his contemporaries’ understanding, miracles; that is to say, events that were the result of supernatural divine causality. Doubtless he healed the sick and cast out demons.
Even Bultmann says miracles and exorcisms belong to the historical Jesus. In Bultmann’s day these stories were considered legendary because of the supposed influence of Greco-Roman mythology on the Gospels, but scholars today realize this influence was virtually nil. They now believe the role of Jesus as a miracle worker must be understood against the backdrop of first-century Palestinian Judaism, where it fits right in.
The only reason to be skeptical that these were genuine miracles would be philosophical—do you believe that such events can occur or not?
Adapted from interview with Dr. William Lane Craig