The dictionary defines demon as:
An Evil Spirit
A source or agent of Evil
Supernatural being of Greek Mythology, intermediate between Gods and Men
The bible says in Genesis Chapter 2; 15Then the Lord God took the man and put him in the garden of Eden to tend and keep it. 16And the Lord God commanded the man, saying, “Of every tree of the garden you may freely eat; 17but of the tree of the knowledge of good and evil you shall not eat, for in the day that you eat of it you shall surely die.”
Now in Chapter 3; 1Now the serpent was more cunning than any beast of the field which the Lord God had made. And he said to the woman, “Has God indeed said, ‘You shall not eat of every tree of the garden’?” 2 And the woman said to the serpent, “We may eat the fruit of the trees of the garden; 3 but of the fruit of the tree which is in the midst of the garden, God has said, ‘You shall not eat it, nor shall you touch it, lest you die.’”
4 Then the serpent said to the woman, “You will not surely die. 5 For God knows that in the day you eat of it your eyes will be opened, and you will be like God, knowing good and evil.”
6 So when the woman saw that the tree was good for food, that it was pleasant to the eyes, and a tree desirable to make one wise, she took of its fruit and ate. She also gave to her husband with her, and he ate. 7 Then the eyes of both of them were opened, and they knew that they were naked; and they sewed fig leaves together and made themselves coverings.
8 And they heard the sound of the Lord God walking in the garden in the cool of the day, and Adam and his wife hid themselves from the presence of the Lord God among the trees of the garden.
I never counted how many commentaries say God is not walking, Just wind blowing. Listen in Genesis 5:22 Enoch walked with God three hundred years. Genesis 6:9 This is the genealogy of Noah. Noah was a just man, perfect in his generations. Noah walked with God. Genesis 18 Abraham had a meal with the Lord and 2 Angels, you either believe the Bible or get rid of it. Now back to Adam and Eve. God removed them from the Garden of Eden, they had 2 sons one Cain and the other Able.
Genesis 4: Now Adam knew Eve his wife, and she conceived and bore Cain, and said, “I have acquired a man from the Lord.” 2 Then she bore again, this time his brother Abel. Now Abel was a keeper of sheep, but Cain was a tiller of the ground. 3 And in the process of time it came to pass that Cain brought an offering of the fruit of the ground to the Lord. 4 Abel also brought of the firstborn of his flock and of their fat. And the Lord respected Abel and his offering, 5 but He did not respect Cain and his offering. And Cain was very angry, and his countenance fell.
6 So the Lord said to Cain, “Why are you angry? And why has your countenance fallen? 7 If you do well, will you not be accepted? And if you do not do well, sin lies at the door. And its desire is for you, but you should rule over it.”
Now what do you think was in the fruit that came off that tree, poison? No, that would kill them fast. V7 says sin lies at the door and it’s desire is for you. But you should rule over it. What does it mean to rule over it? How can we rule over it? Is sin a Demon? The King James Version of the Bible says rule over him, is “him” a living thing? Lets go back to Genesis 3:14: 14 So the Lord God said to the serpent:
“Because you have done this, You are cursed more than all cattle, And more than every beast of the field; On your belly you shall go, And you shall eat dust All the days of your life. 15 And I will put enmity
Between you and the woman, And between your seed and her Seed; He shall bruise your head, And you shall bruise His heel.”

This sounds like Jesus in Matthew 10: 34 “Do not think that I came to bring peace on earth. I did not come to bring peace but a sword.” 35 For I have come to ‘set a man against his father, a daughter against her mother, and a daughter-in-law against her mother-in- law’; 36 and ‘a man’s enemies will be those of his own household.’
The Bible says you have to have Faith. I know where Noah’s Ark is at because in Genesis 8:4 Then the ark rested in the seventh month, the seventeenth day of the month, on the mountains of Ararat.
But has anybody found it? No. When the Lord wants it found, it will be found. In Daniel 12:4 “But you, Daniel, shut up the words, and seal the book until the time of the end; many shall run to and fro, and knowledge shall increase.”
If we found the Ark before God wanted it found, it would take all the faith from the Bible. You have to have faith in something you cannot see with your eyes, but with your heart.
Now back to Genesis 2: 8 The Lord God planted a garden eastward in Eden, and there He put the man whom He had formed. 9 And out of the ground the Lord God made every tree grow that is pleasant to the sight and good for food. The tree of life was also in the midst of the garden, and the tree of the knowledge of good and evil.
There are 2 realms in the Bible, the earthly realm and the heavenly realm. God created man in the earthly realm, and placed him in the heavenly realm. They were disobedient and placed back in the earthly realm, where we are being tested with trials, temptations, tribulations, to see if we choose to be obedient to the Lord or not, to accept Jesus in our Heart or not.
Back to the Demons, inside of us, like it or not, we have choice, we have good, which is your conscience (Holy Spirit), and we have evil, which is a Demon. Remember the Demon wants to steal, kill, and to destroy you. Your conscience is the Holy Spirit, and wants to give you life .
In John 10 10 The thief does not come except to steal, and to kill, and to destroy. I have come that they may have life, and that they may have it more abundantly.
11 “I am the good shepherd. The good shepherd gives His life for the sheep.
Each of us has a place for Good and Evil. Built in our Temple House. Remember Matthew 12:43 “When an unclean spirit goes out of a man, he goes through dry places, seeking rest, and finds none. 44 Then he says, ‘I will return to my house from which I came.’ And when he comes, he finds it empty, swept, and put in order. ( He gave his life to Jesus, but look what happens next, the enemy comes with help to win him back to evil) 45 Then he goes and takes with him seven other spirits more wicked than himself, and they enter and dwell there; and the last state of that man is worse than the first. So shall it also be with this wicked generation.”
Now in Acts 12: 21 So on a set day Herod, arrayed in royal apparel, sat on his throne and gave an oration to them. 22 And the people kept shouting, “The voice of a god and not of a man!” 23 Then immediately an angel of the Lord struck him, because he did not give glory to God. And he was eaten by worms and died.
In Isaiah 66: 24 “And they shall go forth and look Upon the corpses of the men Who have transgressed against Me. For their worm does not die, And their fire is not quenched. They shall be an abhorrence to all flesh.”
Now you can translate worms to maggots or larva. Anyone with fruit trees and does not spray them will have worms in their fruit. I wonder if the fruit Eve picked off the tree of Good and Evil had something in it? Maybe a maggot or a worm? Now in Mark 9: 42 “But whoever causes one of these little ones who believe in Me to stumble, it would be better for him if a millstone were hung around his neck, and he were thrown into the sea. 43 If your hand causes you to sin, cut it off. It is better for you to enter into life maimed, rather than having two hands, to go to hell, into the fire that shall never be quenched— 44 where ‘Their worm does not die And the fire is not quenched.’(If you were reading a NIV, ESV TGNT, or the NLT, v44 and 46 would be missing.)45 And if your foot causes you to sin, cut it off. It is better for you to enter life lame, rather than having two feet, to be cast into hell, into the fire that shall never be quenched— 46 where ‘Their worm does not die, And the fire is not quenched.’ 47 And if your eye causes you to sin, pluck it out. It is better for you to enter the kingdom of God with one eye, rather than having two eyes, to be cast into hell fire—
Where their worm does not die and the fire is not quenched, I would have to conject to spend eternity in a fire with a worm eating on you would be so terrible, I am having a terrible time imagining it.
Remember knowing Jesus and helping others is the rent we pay for our room in Heaven.