‘These have one mind and they give their power and authority to the beast. These shall war against the Lamb and the Lamb will overcome them, for he is Lord of Lords, and King of Kings, and those who are with Him, called, chosen and faithful, will also overcome.'
Note the emphasis on the fact that the ten kings are of one mind. They fall into line with the Beast's aims and purposes. And this results in war with the Lamb of God. But the Lamb will overcome them because he is Lord of Lords and King of Kings. And those who belong to the Lamb will also overcome, for they are called, chosen and faithful. We are not, of course, to see here a literal war between the Beast acting on earth and the Lamb. The Beast's battle is rather with Lamb's followers (compare Revelation 20:9). Had he literally fought the Lamb it would have been no contest, as the Lamb's titles indicate. So the idea is that these rulers will set themselves against God's people, thus taking on the Lamb Himself, although not directly.
This ‘war' is described more fully in Revelation 19:11-21, evidence again that we have moved to the end time. ‘Lord of Lords and King of Kings' sets Christ well above the ‘ruler of the kings of the earth'. The rulers are at one with the beast and totally committed because theirs is a religious devotion. They are (perhaps unconsciously) committed to Satan. But they are doomed to defeat because of the power of the Lamb.
For the encouragement of the churches John then connects the churches themselves with the triumphant Lamb. They are called, chosen and faithful and are overcomers. ‘Called' and ‘chosen' are two words continually applied to Christians, see Ephesians 1:4; Romans 8:28-30; Matthew 20:16; Matthew 22:14; Mark 13:20; John 13:18; 2Th 2:13; 1 Peter 2:4; 1 Peter 2:9; Romans 1:6; Romans 9:24; 1 Corinthians 1:9; Ephesians 4:1; Eph 4:4; 1 Thessalonians 2:12; 2 Thessalonians 2:14; 2 Timothy 1:9; 1 Peter 1:1-2; 1Pe 1:15; 1 Peter 2:21; 1 Peter 5:10; 2 Peter 1:3). ‘Overcomers' is the favourite term in Revelation for God's faithful people.