What does Matthew 13:56 mean?

The people of Nazareth are convinced that they already know who Jesus is; whatever He's saying or doing now cannot change their views. Jesus grew up among them (Matthew 13:54–55). They all went to the synagogue together as children. His sisters were all present in the room. They knew His adoptive father Joseph, who might have been dead by now. His mother Mary was there. They're not truly asking where Jesus obtained wisdom and power. Rather, they're being sarcastic, the way someone might snap "who put you in charge?" to a peer.

If the people had simply been marveling at the unexpected, their reaction might have made more sense. Had these questions been followed by repentance, it would imply sincerity. Instead, their astonishment caused them to reject any idea of Jesus being important, let alone being the Messiah. As the following verse shows, they felt insulted by Jesus instead of worshiping Him. Their comfortable, established concept of Christ was too ingrained to be changed.

The same mistake can be made today. Both for claimed Christians as well as non-believers, it's possible to prefer traditions, myths, and assumptions about Christ rather than accurate teaching. When presented with new information, some will respond by waving it away, claiming they "already know" what they need to know.