As foretold in the eighteenth of Revelation, the third angel's message is to be proclaimed with great power by those who give the final warning against the beast and his image: "I saw another angel come down from heaven, having great power; and the earth was lightened with his glory. And he cried mightily with a strong voice, saying, Babylon the great is fallen, is fallen, and is become the habitation of devils, and the hold of every foul spirit, and a cage of every unclean and hateful bird. For all nations have drunk of the wine of the wrath of her fornication, and the kings of the earth have committed fornication with her, and the merchants of the earth are waxed rich through the abundance of her delicacies. And I heard another voice from heaven, saying, Come out of her, My people, that ye be not partakers of her sins, and that ye receive not of her plagues. For her sins have reached unto heaven, and God hath remembered her iniquities. Reward her even as she rewarded you, and double unto her double according to her works: in the cup which she hath filled fill to her double." Revelation 18:1-6.
 

This is the message given by God to be sounded forth in the loud cry of the third angel.
 

Those whose faith and zeal are proportionate to their knowledge of the truth will reveal their loyalty to God by communicating the truth, in all its saving, sanctifying power, to those with whom they associate. Their lives of holiness and unselfish service will be in conformity with the vital principles of the kingdom of heaven.