Amazement in the Gospel does not always lead to faith. People are amazed to see Jesus liberate a dumb man from the evil power that prevented him from speaking, But, rather than seeing here the clear intervention of God's saving power, they see in Jesus the power of another evil spirit.
Then, on top of that, they ask Jesus to give some special sign of his authority and identity! Jesus shows up the contradictions of their position. First, he has just given a powerful sign but they choose not to see it as such. Secondly, a divided household can only collapse. Why would Satan be undoing his own work? And, if it is through Satan that Jesus casts out Satan, by what power do other exorcists among them do it? If the answer is by God's power, why should they make an exception of Jesus?
Both readings today urge us to listen carefully to God speaking to us in our lives. Let us not be blinded by prejudice of any kind which might prevent us from recognizing the signs or the voice or the hand of God in people and experiences we have during any ordinary day. There must be many times when we write off people and events and so fail to realize that God is saying something important to us through them. They may be saints or sinners - it does not matter. God can and does use any channel to reach us.
Oh, that today you would listen to His voice!