In this chapter we see people who are opposed to Jesus and those who decide to follow Him. Both groups are seeing and hearing the same things but reacting differently. One group goes so far as to say Jesus is doing miracles using Satan’s (Beelzebul’s) power. Jesus says this sin is unforgivable.
It is common for two people to see the same thing and come to very different conclusions. One person sees useless junk and another person sees a beautiful antique. In Jesus’ case, they saw the Son of God or a dangerous sinner. Those who saw him as a dangerous sinner could not possibly be forgiven, because they were rejecting Jesus. Jesus isn’t something in-between, like a great teacher or a really good person. He cannot have said what he said about himself unless he was the Son of God or a liar. Which is he for you?