No authority to torture
One of the most common false teachings regarding the devil is that God will allow him to live forever in order to torture sinful humans into eternity. Below are two of MANY reasons why Satan is not able to do this.
Satan's existence will end
Satan's ultimate judgment for all the pain and suffering he brought into the universe will be his utter and total DESTRUCTION at the hands of God. The Eternal makes it plain, through Ezekiel the prophet, that there will be a time when his adversary will no longer exist.
. . . I will bring you to ashes upon the earth, before the eyes of all who see you. 19. All who know you among the people shall be astonished at you; you became a terror, and YOU WILL NOT BE ANY MORE (Ezekiel 28:18 - 19, HBFV throughout unless stated)
The devil's destiny is the lake of fire (Revelation 20:10). Satan (who is composed of spirit and cannot feel physical pain) would NOT be punished for his sins if he were merely allowed to continue living in a place that was "hot." The unique "heat" of the lake of fire, however, will punish both unrepentant spirits and flesh-based beings (who have already lived in torment from the day they fully rejected God) by putting them out of existence FOREVER. Please see our article on Satan's destiny for more information on this fascinating topic.
No humans to torture
The second reason why Satan cannot torture humans in some eternal Hell is that NO HUMANS will exist in which to do so!
16. For God so loved the world that He gave His only begotten Son, so that everyone who believes in Him may not PERISH, but may have everlasting life (John 3:16)
The Greek word translated "perish" is apollumi, Strong's Concordance #G622, which means "to destroy." It does not refer to the physical death that ALL humans must experience (Romans 6:23, 1Corinthians 15:22) but to ANOTHER death that lasts forever.
John 3:16 teaches us, in summary form, that those who repent, believe in Christ and obey his words will be given everlasting life sometime after they die. Those who do not believe, however, who refuse to accept the Messiah and refuse to repent, will perish (be destroyed). Hence, John is contrasting the two ultimate destinies God offers each human - an everlasting spirit life with him or its exact opposite, everlasting death (ceasing to exist). The Bible does not teach the ridiculous notion of a "middle ground" of punishment, where humans are given "immortal flesh" that never decays and is able to experience excruciating pain and untold suffering into eternity. For further study please read "Do we have an immortal soul" and "What does the Bible say about Hell."
Lucifer, as God's greatest creation before the time of man, almost certainly had the freedom to go wherever he wanted to either in the physical or spiritual universe. After he perverted himself to become the devil, however, his freedom was greatly curtailed.
Scripture indicates that Satan's freedom of movement is somewhat limited. He is currently able to travel back and forth to God's throne in order to accuse humans in his presence (Job 1, 2 and Revelation 12:10). He also spends quite a bit of time roaming around the earth looking for things to do (Job 1:7, 2:2). Nowhere in Scripture is it ever stated or implied that, after he sinned, he continued to have the freedom to roam the universe (e.g. he cannot bring his mayhem to other galaxies).
We cannot be separated from God
The devil has not been given the authority to separate us from God against our will. On this point, the apostle Paul writes the following.
35. What shall separate us from the love of Christ? . . . 38. For I am persuaded that neither death, nor life, nor angels (whether they be good or bad), nor principalities (angelic beings of the highest rank), nor powers (no matter how powerful righteous or fallen angels may be), nor things present, nor things to come, 39. Nor height, nor depth, nor any other created thing, shall be able to separate us from the love of God, which is in Christ Jesus our Lord (Romans 8:35, 38).
Jesus made an interesting statement regarding how the devil and his demons treat each other in the spirit world. When some Jewish religious leaders viciously accused him of casting out demons through the power of Beelzebub (Satan) he stated the following.
"Every kingdom divided against itself is brought to desolation, and every city or house divided against itself shall not stand. 26. And if Satan casts out Satan (meaning demons who follow his ways and consider him their leader), he is divided against himself. How then shall his kingdom stand?" (Matthew 12:25 - 26).
Jesus' logic is profound and simple. Satan the devil (or, by implication, any demon) COULD "cast out" or force a less powerful demon to leave a person but does not do so. The reason why he (and any evil spirit) chooses not to do this is that it would weaken their collective evil efforts (their "kingdom") against God. In the minds of demons, their commonly shared intense hatred of the Almighty and all that is good unites them so strongly that they choose not to fight among themselves or hinder each other's demonic efforts!