There is an expression in English which says, "Seeing is believing". Interestingly it comes from Jesus' words to doubting Thomas who only believed because he had seen (John 20:29).
Capernaum was the base for Jesus and His disciples when they were in the Galilee area. The miracles He performed were the talk of the town; and they clamoured to see more.
The King is kind! Having pronounced judgement on the unrepentant towns, Jesus turned His attention to the many people who were eager to welcome Him - but might have doubted if He really wanted them.
Jesus lived in occupied territory. Israel, God's Promised Land, had been invaded by the Roman army: the people had been conquered. They had to obey Roman laws and pay Roman taxes.