What if a demon doesn’t listen to Satan, or decides to rebel against him, what would happen? Could they die? How does it work if they decide to rebel against Satan?
Before answering your question, let us notice some very good news about Satan. We read in Hebrews 2:14-15, “Therefore, since the children share in flesh and blood, He Himself likewise also partook of the same, that through death He might render powerless him who had the power of death, that is, the devil, and might free those who through fear of death were subject to slavery all their lives.” Unless noted with the reference, all of the Bible verses in this answer are from the NASB. How wonderful it is that the Lord Jesus Christ has rendered Satan powerless through His death on the cross. Every believer on the Lord Jesus has ETERNAL LIFE and is safe from the clutches of Satan. Satan’s final judgment is sure and certain but has not happened yet.
One of your questions is: “Could they (demons) die?” We read in Luke 20:34-36, “Jesus said to them, “The sons of this age marry and are given in marriage, but those who are considered worthy to attain to that age and the resurrection from the dead, neither marry nor are given in marriage; for THEY CANNOT EVEN DIE ANYMORE, BECAUSE THEY ARE LIKE ANGELS, and are sons of God, being sons of the resurrection.” All angels are spiritual beings who cannot die.
Angels are created beings. We read about Satan in Ezekiel 28:15, “You were blameless in your ways from THE DAY YOU WERE CREATED until unrighteousness was found in you.” We know that Satan is an angel. God said about Satan in Ezekiel 28:14, “You were the anointed CHERUB who covers, and I placed you there. You were on the holy mountain of God; you walked in the midst of the stones of fire.” A cherub is a type of angel, so Satan is an angelic being.
There are two main types of angels, commonly referred to by people as “good angels” and “bad angels.” The Bible calls good angels “holy angels” in Matthew 25:31 (KJV) and “chosen angels” in 1 Timothy 5:21. The Bible calls bad angels the ones who have “sinned” (2 Peter 2:4), “unclean spirits” (Matthew 10:1), and “demons” (Mark 1:34).
Satan is in charge of the bad angels. We read in Revelation 12:9, “And the great dragon was thrown down, the serpent of old who is called the devil and Satan, who deceives the whole world; he was thrown down to the earth, and HIS ANGELS were thrown down with him.” Notice that the bad angels are referred to as His (Satan’s) angels. Therefore, he is the commander of the bad angels (demons).
Concerning the parts of your question that ask about demons rebelling against Satan, there is no indication in the Scriptures that demons rebelled or ever will rebel against Satan. Every indication in the Bible is that the good angels are faithful to God and the bad angels are loyal to Satan. Let us see this from the Word.
Speaking about the good angels, we read in Hebrews 1:14, “Are they not all ministering spirits, sent out to render service for the sake of those who will inherit salvation?” In Psalm 91:11 we read, “For He will give His angels charge concerning you, to guard you in all your ways.” We see in Psalm 103:20, “Bless the LORD, you His angels, mighty in strength, who perform His word, obeying the voice of His word!”
In contrast, demons indwell unbelievers with horrible results. We read in Luke 9:42, “While he was still approaching, the demon slammed him to the ground and threw him into a convulsion. But Jesus rebuked the unclean spirit, and healed the boy and gave him back to his father.” We read in Matthew 8:28-29, “When He came to the other side into the country of the Gadarenes, two men who were demon-possessed met Him as they were coming out of the tombs. They were so extremely violent that no one could pass by that way. And they cried out, saying, “What business do we have with each other, Son of God? Have You come here to torment us before the time?”
The demons are aware in verse 29 that they will be judged in a future day at “the time.” There is no indication that the demons would do anything other than continue serving Satan and be tormented someday. Their destiny is certain, and they know that their judgment is coming. We read in Matthew 25:41, “Then He will also say to those on His left, ‘Depart from Me, accursed ones, into the eternal fire which has been prepared for the devil and his angels.’” We read of the coming judgment in Revelation 20:10. “And the devil who deceived them was thrown into the lake of fire and brimstone, where the beast and the false prophet are also; and they will be tormented day and night forever and ever.”
I pray that you, dear reader, will not someday be in that awful place where Satan and his demons are headed. Please agree with God that you are a sinner and trust Christ today as your Savior. Then you can say to the Lord what David did in Psalm 16:11. “You will make known to me the path of life; in Your presence is fullness of joy; in Your right hand there are pleasures forever.” (DJ) (583.2)