Although priests and politicians could not work out who Jesus was - evil spirits had no such problem.  These fallen angels instantly recognised the Lord Jesus Christ as the eternal Son of God, the appointed King of God's Kingdom.  They knew that ultimate power was not in their hands or Satan's: the arrival of Jesus announced that their days of evil were numbered because He would finally destroy them (Mark 1:24). These impure evil spirits spoke through the mouths of the people they had invaded, the men or women who allowed evil to live within them.  The demons would sometimes throw their subjects to the ground, mimicking epilepsy (Mark 9:20) or make them shout out (Mark 5:6-7).

If Jesus had only been a prophet or teacher, the demons would be unmoved.  Instead, they were distinctly agitated.  They could plainly see that Jesus had the full authority of God.  Even so, they taunted Him, as Satan did in the wilderness (Matthew 4:1-7), and when he invaded the willing heart of Judas Iscariot (Luke 22:3), to propel the events which led to the cross.  But all that evil activity was allowed by the Lord.  The impure spirits had no idea that their manipulation of the religious leaders and the crowds, to impale Jesus on the cross, would be followed by His resurrection and signal their final defeat at the end of time.  Jesus came to undo the works of the devil (1 John 3:8).  

The powerful word of Jesus was enough to silence the mocking voices.  It was raw authority.  God had spoken, and there was nothing more to say.  Jesus was in charge.  His timetable to the cross was set and even the demons were forbidden to say anything which would disturb God's plans.

Even today, unexpected things come out of people's mouths, and we say, "What's got into them?"  The answer should be obvious.  It is Jesus alone who can change all that ... which is very good news indeed for those for whom terror seems to live inside them.  Not all evil is the direct consequence of demonic activity.  Our fallen nature has quite enough rebellion to resist the Lord and pursue a wicked path: we must repent and receive the help which the Lord gives to live a life which pleases Him (Romans 13:14).  But we are in a spiritual battle (Ephesians 6:10-12).  The devil certainly exists and when he stirs us to disobey the Word, we must resist him and draw ourselves close to the Lord for protection (James 4:7-8).  We must not let ourselves be intimidated by Satan's tactics and lies - because the Lord who is in us is far greater than the Evil One (1 John 4:4).  Don't forget that Jesus always has the last word.