Is Satan Finally Defeated?

"Now the salvation, the power, and the Kingdom of our God, and the authority of his Christ has come; for the accuser of our brothers has been thrown down, who accuses them before our God day and night" (Revelation 12:10). That verse announces a real, decisive legal defeat. It is not, yet, the same as total and final removal.
Scripture holds both truths together throughout, in an "already, not yet" structure that runs through its whole treatment of this conflict. Revelation 12:9-11 explicitly identifies "that ancient serpent, who is called the devil and Satan" as the accuser of the brothers, now "hurled down" — his legal standing to bring charges before God's court is finished, permanently. And yet this inaugurated defeat coexists with ongoing, though now delegitimized, hostile activity on the earth. Ephesians 6:12 still describes believers' present tense struggle "against the rulers, against the authorities, against the cosmic powers over this present darkness." The full identification of this accuser with the serpent of Genesis 3 is not made explicit anywhere within the Old Testament itself; that identification develops gradually and reaches its canonical climax only in Revelation, where the titles "ancient serpent," "devil," and "Satan" are finally united in a single verse. His ultimate, final destruction remains a distinct future event, still ahead of his present legal disarming (compare Revelation 20:10).
So the accuser's case is closed, but the courtroom he once haunted has not yet been demolished around him. He has been stripped of standing, not yet of all activity — thrown down from the place he once occupied among the sons of God, still permitted, for a time, to prowl the ground he was cast onto. "He has been thrown down" is already true. The full silence that follows is coming, and it is coming for certain.