Conquered by the Blood of the Lamb

Rev. 12:7-12 (ESV)
Now war arose in heaven, Michael and his angels fighting against the dragon. And the dragon and his angels fought back, [8] but he was defeated and there was no longer any place for them in heaven. [9] And the great dragon was thrown down, that ancient serpent, who is called the devil and Satan, the deceiver of the whole world— he was thrown down to the earth, and his angels were thrown down with him. [10] And I heard a loud voice in heaven, saying, "Now the salvation and the power and the kingdom of our God and the authority of his Christ have come, for the accuser of our brothers has been thrown down, who accuses them day and night before our God. [11] And they have conquered him by the blood of the Lamb and by the word of their testimony, for they loved not their lives even unto death. [12] Therefore, rejoice, O heavens and you who dwell in them! But woe to you, O earth and sea, for the devil has come down to you in great wrath, because he knows that his time is short!"

The Devil would stand in the presence of God and accuse us his children of sins, sins actually for which we are truly guilty. These are not false accusations that the Devil charges us with, but he charges us with sins for which we are actually guilty, all of which should give him dominion over us. So he fights in the court room of God for possession of us. Yet he is silenced. He is overcome by the death and resurrection of Christ. There is no longer any room for him in the heavenly courts, he has been cast out. He has been thrown down to earth, where he does everything he can to upset the work of the Gospel, but in the end, he is defeated, and has not claim over us. He is conquered by the blood of the Lamb, that is by the forgiveness that Christ appropriated for us on the cross.