At the cross, Jesus drove out Satan, "the prince of this world" (John 12:31-33>. Today Satan is a usurper. The cross passed initial judgment on him. His claims were destroyed; his claimed authority was invalidated. His defeat was so complete that he has lost his place and authority. The Greek word ekballo means "to drive out, expel." The cross doomed Satan to ultimate expulsion from our world, though he is still active and desperate in his anger and futility. He is the archon, the ruler of this age only until God enforces the judgment of the cross after Christ's return.
At the cross, Jesus "disarmed the powers and authorities" (Col. 2:15>). The word disarmed is from the Greek apekoyo, a double compound meaning "to put off completely, to undress completely and thus render powerless." At the cross, Christ undressed all demon authorities. It is a picture from the ancient oriental custom of stripping the robes of office from a deposed official. At the cross, the leaders and authorities of Satan's forces and kingdom were stripped of their authority and honor. They now have no authority to oppose, intimidate, or harass you.
But that is not all; there is even more in this picture. Paul says Christ "made a public spectacle of them, triumphing over them by the cross" (v.15>). This again is an illustration taken from ancient history. When a conquering emperor returned from a great victory, he was often given a triumphal procession. The victor and his army marched through streets lined by cheering thousands. While the musicians played, chariots and soldiers carried the looted treasures of the defeated king, and he and his general or other selected prisoners were led in chains, their shame openly displayed.
The Greek word edeigmatisen means "to make a public exhibition." During the interval between Christ's death and resurrection, when He announced (ekarussen) Satan's defeat at the cross to the evil spirits in prison (I Peter 3:19>), in symbolism Christ marched triumphantly through the spirit prison, with Satan and his demonic rulers chained in inglorious defeat behind Him. He made a public spectacle of their defeat, says Paul, and now every demonic being knows his cause is defeated forever, his satanic lord's authority stripped from him, and his own doom waiting for the appointed time (Matt. 8:29>).
At the cross, Satan and his unclean spirits were destroyed (Heb. 2:14>). The word destroy is from the Greek katargeo, which means "to put out of action, to make useless." It is used repeatedly to show how through the death and the return of Christ (parousia), the powers of destruction that threaten man spiritually are put out of action. In I Corinthians 15:24>, this includes all dominion of demonic authority and power. In verse 26>, death itself will be the last enemy to be rendered useless.
All these are "coming to nothing," including Satan himself (Heb. 2:14>) and his demonic leaders (I Cor. 2:6>).