Mark 9:20
We have several other instances where the forces of darkness had quite strange reactions to the Lord Jesus. Because they knew who he was, they were naturally afraid of him. This particular demon was a little different, however. For whatever reason, he could not speak.
Frankly, it seems strange to say that a demon would not be able to speak. So, is necessary to say that we really don’t understand what the actual situation was. The Scriptures do not give us a lot of specifics or details when it comes to description of the demonic world. What we do know is that Jesus refers to this demon as a deaf and dumb spirit. Thus, whether this particular demon was deaf and dumb by choice, or by some detail of his makeup, he did not speak.
As a result, the temper tantrum we have here is the only thing that the demon could do to express his displeasure over the presence of the Christ.
Heavenly Father, thank you for your great wisdom! You know what you should tell us, and what we don’t really need to know. You always give us the truth that we need for our lives. Thank you for your power! It is wonderful to know that Christ is more powerful than the god of this world. By the Lord Jesus we can have victory in our lives, regardless of the activities of the kingdom of darkness. Thank you for your love for us! In the name of Lord Jesus Christ I pray and praise You, Amen.