Fear of demons and evil spirits appears in every culture and with good reason. After all, demons are supernatural creatures and thus when it comes to sheer strength, these evil beings are vastly more powerful than even the strongest human being. Consequently, we find it easy to understand why people around the world have developed all manner of superstitions that they think will help them break free of the devil's influence. They know they are not strong enough to stop the devil themselves, so they come up with other means of countering the influence of evil spirits.
As Christians, we know that these superstitions have no effective power to drive Satan out. Only one person can do that, namely, God Himself. And that is one of the many lessons we learn from the account of the Gerasene demoniac. Our Lord is able to defeat spiritual enemies because, as the demons recognized, He is "Son of the Most High God" (Mark 5:7).
Legion's addressing of Jesus in such a manner is notable for several reasons. First, Legion likely addressed Christ in this way because the demons were trying to gain some advantage over Him. People in that day commonly believed that to speak another person's name would give the speaker some power over the named individual. Thus, Legion spoke the fullest name of Jesus in hopes of keeping the Lord from driving them out.
Yet, the encounter shows that Legion knew such an attempt was hopeless. The possessed man fell to the ground in the encounter with Jesus, begging Him not to torment the spirits (vv. 6–7). The demons could not help but bow to Jesus as Lord even before He exorcised them. The kingdom of darkness does not exercise a power or authority that is equal to that of the King of kings and Lord of lords. It can act only according to the sovereign permission and power of the triune God. John Calvin comments, "Hence we infer, that the whole of Satan's kingdom is subject to the authority of Christ."
The name Legion indicates that many demons possessed the tormented man. A legion of Roman troops in Jesus' day numbered about fifty-six hundred soldiers, but this does not mean that the same number of evil spirits had taken control of the Gerasene demoniac. The term was used colloquially to refer to a large number of individuals. Jesus cast out a great many devils from the possessed man even if we do not know the precise number.
John Calvin comments on this episode, "It was a magnificent display of the power of Christ, that by his voice not one devil, but a great multitude of devils, were suddenly driven out." That Jesus could cast out so many demons shows that He was more than a mere man. Rather, He was—and remains—God. We can trust Him to break spiritual oppression and preserve us forever in His kingdom.