In Revelation 19 we have a picture of the end of all deceivers, persecutors, tormentors, and tempters. They suffer utter doom. They are completely vanquished. And the hosts of heaven rejoice in their demise. They realize how destructive those are who attack followers of Jesus. They realize how much Christians have suffered for the faith. And now that it is ended, they rejoice in God's vindication. All the pain, tears, troubles, and disappointments have actually happened. There is no guarantee of a painless life for Jesus' followers. In fact, the opposite is true: "If they persecuted me, they will persecute you," Jesus says (John 15:20).
But all persecution - as real, horrific, distressing, and terrible as it may be - will come to an end. The world, the devil, and our flesh may attack. But God's people will be saved. And we will join all the redeemed in praising the One who has saved us. Hallelujah!