Revelation 15:1: “And I” [John] “saw another sign” [vision] “in heaven, great and marvellous, seven angels having the seven last plagues; for in them is filled up the wrath of God.”
Revelation 15:2: “And I saw as it were a sea of glass mingled with fire:” [See Revelation 4:6] “and them” [Those of the 144,000/Saints] “that had gotten the victory over the BEAST, and over his image, and over his mark, and over the number of his name, stand on the sea of glass, having the harps of God.”
Revelation 15:3: “And they sing the song of Moses the servant of God, and the song of the Lamb,” [See Revelation 14:2-5] “saying, Great and marvellous are thy works, Lord God Almighty; just and true are thy ways, thou King of saints.”
Revelation 15:4: “Who shall not fear thee, O Lord, and glorify thy name? for thou only art holy: for all nations shall come and worship before thee;” [See Isaiah 66:23] “for thy judgments are made manifest.”