There’s a common pattern in domestic abuse cases, with the abuser professing his love and apologizing, then losing control and lashing out again, then again professing his love and sorrow, and so forth. In such cases its pretty clear that the external truth – a swinging fist – does not match the love that supposedly exists. On the other hand, when someone professes love and acts in ways that are tender and caring, the external truth – the kind actions – tend to confirm that the love is real.

That’s what the Bible means by being a "witness": It represents using what we know, the truth in front of our noses, to judge the nature of love. In this case, the witness is John, who represents the external, literal meaning of the Bible, and the "light" is divine truth brought to the world by Jesus. So John was re-establishing the Word – the laws and prophets of the Old Testament – so that Jesus could show the perfect love and truth that fill it internally. With the two in harmony, those who were willing would be able to know that Jesus was the Lord, an expression of the ultimate, creative, eternal love.

(Reference: The Apocalypse Explained 27 [2])

1068. Verses 12-14. And the ten horns which thou sawest are ten kings, who have received no kingdom as yet; but they receive power as kings one hour with the beast. These have one mind, and shall deliver up their power and authority to the beast. These shall fight with the Lamb, and the Lamb shall overcome them, for he is Lord of lords, and King of kings; and those that are with him, are called, and chosen, and faithful.

"And the ten horns which thou sawest are ten kings," signifies the truths of the Word as to power; "who have received no kingdom as yet; but they receive power as kings one hour with the beast," signifies with those who have not thus acknowledged the Lord's power over heaven and earth as transferred to man, and who have attributed Divine sanctity to the Word, and not so to the edicts of the Pope.

"These have one mind, and shall deliver up their power and authority to the beast," signifies agreement that the Word is the Divine truth, on which the church as to its doctrine must depend.

"These shall fight with the Lamb, and the Lamb shall overcome them," signifies that they shall have a contest with those who are meant by the whore about the sanctity of the Word, and the Lord's power to save men; and that the Lord will rescue those who are willing to be led of Him by the Word, and not by the woman, the whore; "for he is Lord of lords, and King of kings," signifies because the Lord is good itself and truth itself, and thence almighty; "and those that are with him, are called, and chosen, and faithful," signifies that those who love the Lord, and the neighbour, and have the faith of charity, are in the truth concerning the Lord's Divine power and the Divine sanctity of the Word.