In my last post, I have tried to explain what demons are and their origins. Following up from there, I would like to explain to you their nature.
In the previous post, I quoted from Enoch 15:2b-12 (emphasis mine):
And go, say to the Watchers of heaven, who have sent thee to intercede for them: “You should intercede” for men, and not men 3 for you: Wherefore have ye left the high, holy, and eternal heaven, and lain with women, and defiled yourselves with the daughters of men and taken to yourselves wives, and done like the children 4 of earth, and begotten giants (as your) sons? And though ye were holy, spiritual, living the eternal life, you have defiled yourselves with the blood of women, and have begotten (children) with the blood of flesh, and, as the children of men, have lusted after flesh and blood as those also do who die 5 and perish. Therefore have I given them wives also that they might impregnate them, and beget 6 children by them, that thus nothing might be wanting to them on earth. But you were formerly 7 spiritual, living the eternal life, and immortal for all generations of the world. And therefore I have not appointed wives for you; for as for the spiritual ones of the heaven, in heaven is their dwelling. 8 And now, the giants, who are produced from the spirits and flesh, shall be called evil spirits upon 9 the earth, and on the earth shall be their dwelling. Evil spirits have proceeded from their bodies; because they are born from men and from the holy Watchers is their beginning and primal origin; 10 they shall be evil spirits on earth, and evil spirits shall they be called. [As for the spirits of heaven, in heaven shall be their dwelling, but as for the spirits of the earth which were born upon the earth, on the earth shall be their dwelling.] And the spirits of the giants afflict, oppress, destroy, attack, do battle, and work destruction on the earth, and cause trouble: they take no food, but nevertheless 12 hunger and thirst, and cause offences. And these spirits shall rise up against the children of men and against the women, because they have proceeded from them.
From the passage above, you will gather that evil spirits ‘cause trouble‘; they ‘afflict, oppress, destroy, attack, do battle‘; they can ‘cause offences‘ and have the potential to ‘work destruction on the earth‘.
The bible also speaks of the trouble that evil spirits can cause, and the great strength that they may have:
Then the man who had the evil spirit jumped on them and overpowered them all. He gave them such a beating that they ran out of the house naked and bleeding. (Acts 19:16, NIV; emphasis mine)
When he arrived at the other side in the region of the Gadarenes, two demon-possessed men coming from the tombs met him. They were so violent that no one could pass that way. (Matthew 8:27-29; emphasis mine)
Despite their great strength, believers in Jesus Christ haven been given authority over demons (Luke 9:1-2, NIV; emphasis mine):
When Jesus had called the Twelve together, he gave them power and authority to drive out all demons and to cure diseases, 2 and he sent them out to proclaim the kingdom of God and to heal the sick.
Hallelujah! Glory to God!