That Jesus was a miracle worker is central to the Christology of the New Testament Gospels and Acts. In Mark, the earliest Gospel, 17 stories of miracles appear in the first eight chapters. Most of the stories are repeated by Matthew and Luke. In Peter’s Pentecost speech, he recalls Jesus’ ministry by saying that Jesus was “a man designated … by God with deeds of power, wonders, and signs that God did through him” (Acts 2:22). Some scholars tell us that a so-called Signs Source was incorporated into the Gospel of John, according to which 12 signs or miracles are recounted in chapters 1 through 12. The ending of the original Gospel of John even assures the reader that Jesus “did many other signs in the presence of his disciples, which are not written in this book” (John 20:30; chapter 21 was added later).
How are we to understand the miracles Jesus performs, as related in the New Testament? This is not the same as asking whether they happened. Some may have happened; others should probably be interpreted symbolically.
But all the miracle stories impart a theological lesson. That is why they are there. This message is what we are to understand from them.