Man needs to see the miraculous continually. Jesus went around doing good and healing not just because it was in his nature to heal people, but also so that people would believe. In John 4 Jesus says to a man whose son was dying, "Unless you people see signs and wonders, you simply will not believe." Here's the text and the context:
John 4:46-50- Therefore He came again to Cana of Galilee where He had made the water wine. And there was a royal official whose son was sick at Capernaum. 47 When he heard that Jesus had come out of Judea into Galilee, he went to Him and was imploring Him to come down and heal his son; for he was at the point of death. 48 So Jesus said to him, “Unless you people see signs and wonders, you simply will not believe.” 49 The royal official *said to Him, “Sir, come down before my child dies.” 50 Jesus *said to him, “Go; your son lives.” The man believed the word that Jesus spoke to him and started off.
If you read this with a certain perspective, it could come across as a rebuke to the royal official, but I don't believe that's the way to see this situation. The context of this situation starts by reminding us of the miracle of water being turned to wine. Most likely the royal official was aware of the water to wine miracle. Nevertheless, he needed a miracle at that moment and the miracle of water to wine was yesterday's news. Man needs to continually see the hand of God helping him.
With that said, I believe it's possible to read Jesus' words this way: "Unless you people continue to see signs and wonders, you simply will not believe."