Ironically, Jesus goes from Nazareth to Capernaum, the town of which His neighbors were jealous. Like the people of Nazareth they were “…astonished at his teaching…” but unlike the Nazoreans they were astonished because “…he taught with authority.”
They were listening to Him: they had faith in Him.
Because of that faith He was able to do a great work in their midst, casting a demon out of a man, and by this His authority was fully revealed: if even a demon—a rebellious angel—had to listen to Jesus, then those present ought to heed Him as well! But it would do nothing for them were Jesus to show up in their town, drive out a demon, and then preach and teach. They would only be convinced in their minds, their enthusiasm, but they would not be converted to believe in Him.
“Blessed are the clean of heart,” Jesus has said, “for they shall see God,” (Matthew 5:8). The people of Nazareth already knew what they wanted to see, and Jesus preaching was not it. The people of Capernaum desired God first, and listened to Jesus, and by their faith they witnessed a miracle. When we listen to Jesus, when He becomes our Lord and Master, only God knows what we will behold.