Short answer: Satan was released for that "short time" after the thousand years ended at the ascension of Christ on His resurrection day in AD 33. That was when Satan and his devils were cast out of heaven down to earth to once more deceive the nations in "great wrath". Revelation 12:12 describes the outcome of this AD 33 war in heaven when "the accuser of the brethren" lost his ability to charge the believers with anything, once our Great High Priest was enthroned that day as our intercessor before God. John then pronounced "woe" upon the inhabitants of the world in his days, since Satan had come down to them at that time to once again deceive the nations.
The question remains as to WHY Satan and his devils were released on earth to harass the inhabitants of the world. WHY release Satan to again deceive the nations as he had done before his deception of them had been bound for the thousand years? God had a distinct purpose for releasing Satan after the literal thousand years ended in AD 33, and it is revealed in the Scriptures from the OT to the NT.
Satan and his devils were the tool Christ was going to use to punish those of His own first-century generation of countrymen who had rejected, betrayed, and murdered Him and His servants. He was going to "destroy those murderers and burn up their city" of Jerusalem, just as He predicted in the parable in Matthew 22:1-14.
Christ had already predicted in Matthew 12:43-45 that all the unclean spirits which He had been casting out of Israel's citizens would return along with seven-fold numbers of unclean spirits more wicked than the others had been. This would render the "last state" of that wicked first-century generation worse that its "first state" when Christ had been ministering among them.
Christ had also spoken in Matthew 12:24-30 about the devils He had been casting out. The Pharisees accused Christ of casting out devils by the power of Beelzebub, prince of the devils. Christ retorted, "If I by Beelzebub cast out devils, by whom do your children cast them out? therefore THEY" (the devils) "shall be your judges." If the Pharisees were going to insult Christ by saying He was casting out devils by Beelzebub's power, then Christ was going to use the devils which even these Pharisees had been casting out to return in judgment upon those who had been doing those exorcisms. And the number of devils would be multiplied seven times as many and much more wicked than the others had been. Satan's kingdom was going to be divided against itself, and would thereby come to an end.
Christ also predicted the time when Satan and his devils would be cast out of heaven down to earth to judge that first-century generation. In John 12:31, just five days before the Passover, Christ warned His disciples, "NOW is the judgment of this world: NOW shall the prince of this world be cast out." Satan and his devils would be "cast out" of heaven down to earth at Christ's ascension on His resurrection day (when the thousand years was finished), and they would be used for "the judgement of this world" for that "short time" the Satanic realm had left to exist. This is why Satan was described as "having great wrath, knowing that he hath but a short time" after Christ's resurrection day to wreak havoc in the world. This "short time" of Satan's release in Rev. 12:12 is the same as the "little time" of Satan's release in Rev. 20:3 after the thousand years was finished.
Christ repeated His warning on the night of the Last Supper of Satan's soon coming in John 14:31. "Hereafter I will not talk much with you: for the Prince of this world cometh, and hath nothing in me." Satan would soon be cast out of heaven after that war with Michael and his angels, and would come down to earth to deceive the nations once more. This is why Peter warns his own generation in those days that "Satan as a roaring lion walketh about, seeking whom he may devour" (1 Peter 5:8.) Satan's renewed deception of the nations was in full swing after the thousand years had ended in AD 33.
Revelation 18:2 describes how "Babylon the Great" (old Jerusalem) would become "a habitation of devils, and a prison of every unclean spirit..." The entire Satanic realm of Satan and his devils and unclean spirits would be imprisoned within the city of Jerusalem in the nation's "last state". This is what composed the "great tribulation" period which had never been seen before, and would never again be duplicated in history to come afterward. The Devil and his angels tormented the besieged inhabitants and were tormented themselves in that "Lake of Fire" environment in the city of Jerusalem which had been "prepared" for them.
Isaiah 24:21-23 also described this same imprisonment of the wicked angels in the city of Jerusalem. God predicted that He would "punish the host of high ones that are on high" by gathering them together along with the kings of the earth (the high priests of Israel). Just like prisoners gathered in a pit, these high priest kings of the earth and the wicked angelic hosts would be "shut up in the prison, and after many days, shall they be found wanting". This means GONE from existence. Neither the high priest kings of the earth nor any of the Satanic hosts would survive this period of imprisonment in the city of Jerusalem leading to its destruction in AD 70.
Our God is superb at multi-tasking. All at the same time during the AD 66-70 period in Jerusalem, He punished and then got rid of the entire Satanic realm as well as punishing those Christ-rejecting Jews of that first-century generation for their murder of His servants. He also got rid of all the "weak and beggarly elements" which had composed the physical temple worship system. This resulted in the manifestation of the NHNE and openly revealed the unshaken New Jerusalem / New Covenant reality in which believers exist today.
The question remains as to WHY Satan and his devils were released on earth to harass the inhabitants of the world. WHY release Satan to again deceive the nations as he had done before his deception of them had been bound for the thousand years? God had a distinct purpose for releasing Satan after the literal thousand years ended in AD 33, and it is revealed in the Scriptures from the OT to the NT.
Satan and his devils were the tool Christ was going to use to punish those of His own first-century generation of countrymen who had rejected, betrayed, and murdered Him and His servants. He was going to "destroy those murderers and burn up their city" of Jerusalem, just as He predicted in the parable in Matthew 22:1-14.
Christ had already predicted in Matthew 12:43-45 that all the unclean spirits which He had been casting out of Israel's citizens would return along with seven-fold numbers of unclean spirits more wicked than the others had been. This would render the "last state" of that wicked first-century generation worse that its "first state" when Christ had been ministering among them.
Christ had also spoken in Matthew 12:24-30 about the devils He had been casting out. The Pharisees accused Christ of casting out devils by the power of Beelzebub, prince of the devils. Christ retorted, "If I by Beelzebub cast out devils, by whom do your children cast them out? therefore THEY" (the devils) "shall be your judges." If the Pharisees were going to insult Christ by saying He was casting out devils by Beelzebub's power, then Christ was going to use the devils which even these Pharisees had been casting out to return in judgment upon those who had been doing those exorcisms. And the number of devils would be multiplied seven times as many and much more wicked than the others had been. Satan's kingdom was going to be divided against itself, and would thereby come to an end.
Christ also predicted the time when Satan and his devils would be cast out of heaven down to earth to judge that first-century generation. In John 12:31, just five days before the Passover, Christ warned His disciples, "NOW is the judgment of this world: NOW shall the prince of this world be cast out." Satan and his devils would be "cast out" of heaven down to earth at Christ's ascension on His resurrection day (when the thousand years was finished), and they would be used for "the judgement of this world" for that "short time" the Satanic realm had left to exist. This is why Satan was described as "having great wrath, knowing that he hath but a short time" after Christ's resurrection day to wreak havoc in the world. This "short time" of Satan's release in Rev. 12:12 is the same as the "little time" of Satan's release in Rev. 20:3 after the thousand years was finished.
Christ repeated His warning on the night of the Last Supper of Satan's soon coming in John 14:31. "Hereafter I will not talk much with you: for the Prince of this world cometh, and hath nothing in me." Satan would soon be cast out of heaven after that war with Michael and his angels, and would come down to earth to deceive the nations once more. This is why Peter warns his own generation in those days that "Satan as a roaring lion walketh about, seeking whom he may devour" (1 Peter 5:8.) Satan's renewed deception of the nations was in full swing after the thousand years had ended in AD 33.
Revelation 18:2 describes how "Babylon the Great" (old Jerusalem) would become "a habitation of devils, and a prison of every unclean spirit..." The entire Satanic realm of Satan and his devils and unclean spirits would be imprisoned within the city of Jerusalem in the nation's "last state". This is what composed the "great tribulation" period which had never been seen before, and would never again be duplicated in history to come afterward. The Devil and his angels tormented the besieged inhabitants and were tormented themselves in that "Lake of Fire" environment in the city of Jerusalem which had been "prepared" for them.
Isaiah 24:21-23 also described this same imprisonment of the wicked angels in the city of Jerusalem. God predicted that He would "punish the host of high ones that are on high" by gathering them together along with the kings of the earth (the high priests of Israel). Just like prisoners gathered in a pit, these high priest kings of the earth and the wicked angelic hosts would be "shut up in the prison, and after many days, shall they be found wanting". This means GONE from existence. Neither the high priest kings of the earth nor any of the Satanic hosts would survive this period of imprisonment in the city of Jerusalem leading to its destruction in AD 70.
Our God is superb at multi-tasking. All at the same time during the AD 66-70 period in Jerusalem, He punished and then got rid of the entire Satanic realm as well as punishing those Christ-rejecting Jews of that first-century generation for their murder of His servants. He also got rid of all the "weak and beggarly elements" which had composed the physical temple worship system. This resulted in the manifestation of the NHNE and openly revealed the unshaken New Jerusalem / New Covenant reality in which believers exist today.
