Overcoming

"Revelation 12:11—"They overcame the devil by the blood of the lamb, for they loved not their lives even unto death"—what does that say? You overcome the devil by the gospel, by believing you are covered by the blood. You overcame by applying and teaching and preaching the blood of Christ, and then by being so sacrificially dedicated to people's lives that you are willing to die rather than run away from a situation. When that happens, when martyrs covered by the blood loving people happens, Satan is defeated. I don't think in order to be seriously engaged in spiritual warfare (where you are freeing people from the powers of the evil one), you have to do exorcisms week in and week out. You have to be a faithful, loving, humble, and repenting teacher—a lover of people. Satan is a liar and therefore he will not abide truth. He is a murderer, and therefore he will not abide love. So if you are a truth-giver and a deep, self-sacrificing lover, you will win." - John Piper, taken from this article