The words Jesus spoke in Capernaum (Luke 4:31-34) must have been similar to what he claimed in Nazareth. In Nazareth Jesus used Scripture to say he was the Messiah, and there the community rose up against him. However, in Capernaum it was a demoniac that rose up against Jesus. One has to wonder if the demoniac in Capernaum tried to do something similar to Jesus that the whole community at Nazareth intended on doing. In other words, the demoniac, at least at first, may have been considered to be in his right mind by the community of Capernaum, because demoniacs, as a rule, are not permitted in the synagogue. The man may even have been a well respected and feared leader in the synagogue. In this context he may have risen up in the assembly to challenge Jesus, saying that his claim to be the Messiah would end in the Romans destroying the nation (cf. Mark 1:24 and John 11:48), or at least the city from which Jesus began gathering a following.
There aren’t many references in the Old Testament to demons or to evil angels, which some suppose to be demons. Nevertheless, this is surprising, given the attention demons have been given in the Gospels. Even so, it is even more surprising that none of the epistles warn believers about them, other than to say men will one day preach their doctrines (1Timothy 4:1). Not even one New Testament writer offers a prescription for getting rid of them or exorcising them from those held under their sway. Only Luke offers even an example of an exorcism (Acts 16:18), yet very little detail is recorded, and what is there can hardly be considered proof of demons being real, sentient wicked spirits.
First century Jewish theology was influenced by Persian dualism, while the Jews were exiled to Babylon. This is implied in the fact that the authority of the rabbis was founded not in Scripture but in quoting one another. Notice how the Babylonian Talmud depicts demonism:
It has been taught: Abba Benjamin says, If the eye had the power to see them, no creature could endure the demons. Abaye says: They are more numerous than we are and they surround us like the ridge round a field. R. Huna says: Every one among us has a thousand on his left hand and ten thousand on his right hand. Raba says: The crushing in the Kallah lectures comes from them. Fatigue in the knees comes from them. The wearing out of the clothes of the scholars is due to their rubbing against them. The bruising of the feet comes from them. If one wants to discover them, let him take sifted ashes and sprinkle around his bed, and in the morning he will see something like the footprints of a cock. If one wishes to see them, let him take the after-birth of a black she-cat, the offspring of a black she-cat, the first-born of a first-born, let him roast it in fire and grind it to powder, and then let him put some into his eye, and he will see them. Let him also pour it into an iron tube and seal it with an iron signet that they should not steal it from him. Let him also close his mouth, lest he come to harm. R. Bibi b. Abaye did so, saw them and came to harm. The scholars, however, prayed for him and he recovered. [Babylonians Talmud: Berachoth 6a] emphasis mine
Imagine for a moment that a group of a dozen or more people wrote a dozen or more books about a controversial subject, concerning which they had very little or no understanding. Consider also that they kept quoting one another as though each one of the dozen or so authors was an expert on the controversial theme in question. Wouldn’t it appear, at least to ordinary folks who also had no knowledge of the subject, that these authors were experts in their field? If we can agree to this principle, then we are able to see how ignorant people can pass themselves off as experts, even though they know little or nothing about the certain theme addressed in their works. All they have to do is continually quote each other, as though the other really knew what he was talking about. Eventually, folks would consider the whole group very knowledgeable (I am speaking here only of the rabbis thoughts on demonic activity, not everything they wrote, but many things written in the Talmud is supported by quoting other rabbis). This is what the rabbis did concerning demons, but Jesus didn’t play their game. He simply spoke out of his own authority (Luke 4:32).
 Hugh Anderson, The Gospel of Mark, NCB (Grand Rapids: Wm. B. Erdmans / London: MM&S, 1976), 90. Cf. Morna D. Hooker, The Gospel According to Mark, BNTC (London: A.&C. Black, 1991), 64.
 The Septuagint offers only eight references: Deuteronomy 32:17; Psalm 91:6; 96:5; 106:37; Isaiah 13:21; 34:13; 65:3, 11.
 Josephus mentions that demons are the spirits of dead men: Wars of the Jews 7.6.3. When referring to a specific root he says: “it quickly drives away those called demons, which are no other than the spirits of the wicked, that enter into men that are alive…”
 Cf. Ps. 91:7 which verse is quoted in some editions.
 The Assemblies of Babylonian students during the months of Elul and Adar, v. Glos.
 For really the lectures are not overcrowded.
 MS. M.: their footprints.
 The demons.3
 He put the powder into his eye.