Revelation 13:7 says, 'It was granted to him [antichrist] to make war with the saints and to overcome them.' This war against the saints takes place in two realms: the earthly and the spiritual. It is not just the antichrist's war, it is also the devil's. Revelation 12:17 says, 'And the dragon [the devil] was enraged with the woman, and he went to make war with the rest of her offspring, who keep the commandments of God and have the testimony of Jesus Christ.'
The earthly warfare is described in Revelation 13, but the spiritual is described in Revelation 12. In 13 the saints are overcome by the antichrist. In other words, they experience suffering and death. But Revelation 12:11-12 says, 'And they overcame him [the dragon/devil/Satan] by the blood of the Lamb and by the word of their testimony, and they did not love their lives to the death.' In other words, the devil may be able to overcome God's people in the physical realm, such as when Jesus was crucified; but in reality they are overcoming him by holding to their faith in the blood and their testimony of Jesus.
Revelation 14:12-13 says, 'Here is the patience of the saints; here are those who keep the commandments of God and the faith of Jesus. Then I heard a voice from heaven saying to me, 'Write:'Blessed are the dead who die in the Lord from now on.'' 'Yes,' says the Spirit,'that they may rest from their labors, and their works follow them.'
We must all prepare for the coming end-time persecution by developing patience (perseverance, endurance) and by keeping the Lord's commandments, which really means keeping the faith. We prepare for the earthly war by preparing ourselves spiritually. The devil thought he had overcome Jesus when He breathed His last breath, but everything changed three days later. The devil didn't really overcome Jesus, He utterly overcame, destroyed, and triumphed over the devil.
We suggest you read our book 'The Glorious Church' and follow the biblical principles we have presented. It can be downloaded for free from this website.