15:2-4 THE SONG OF VICTORY
“And I saw as it were a sea of glass mingled with fire, and those that have the victory over the beast, and over his image, and over his mark, and over the number of his name, standing on the sea of glass, having the harps of God. And they sing the song of Moses, the servant of God, and the song of the Lamb, saying, ‘Great and marvelous are Your works, Lord God Almighty; just and true are Your ways, O King of saints. Who will not fear You, O Lord, and glorify Your name? For You alone are holy; for all nations shall come and worship before You, For Your judgments have been revealed” (Revelation 15:2-4).
The victorious ones, who have been facing the death decree in connection with the mark of the beast, are pictured standing before the throne on a sea of glass just as the plagues are about to be poured out. This does not mean that they have been raptured to heaven and will watch the “time of trouble” from a safe vantage point out of harms way. As in Revelation 7:14, the use of the present participle (Greek nikontas, having the victory) suggests that they are still in the process of having victory over the beast (See 7: In Heaven while on Earth). By faith they are before the throne, while the plagues are falling all around them. Although their lives seem to be in jeopardy, their attention is totally focused on God rather than themselves: “Great and marvelous are Your works, Lord God Almighty; just and true are Your ways, O King of saints. Who shall not fear You, O Lord, and glorify Your name? For You alone are holy.”
Their question, "Who shall not fear You, O Lord, and glorify Your name?" suggests that this group includes those who have responded to the three angels' messages which began with the admonition, "Fear God and give glory to Him" (Revelation 14:7). They are singing “the song of Moses, the servant of God, and the song of the Lamb.” Moses led the children of Israel from Egyptian slavery in the midst of plagues that were similar to the seven last plagues, and they also were pursued (by the Egyptian army). God fought for them during the crossing of the Red Sea, just as He will fight for His people in the
The “song of the Lamb” that they sing along with the "song of Moses" probably refers to the songs recorded in Revelation 5:9-13: “They sang a new song, saying: ‘You are worthy...for You were slain, and have redeemed us to God by Your blood…Worthy is the Lamb that was slain to receive power, and riches, and wisdom, and strength, and honor, and glory, and blessing!” The great multitude singing the "song of Moses…and the song of the Lamb,” which include the declaration, "All nations shall come and worship before You," are prime examples of one of the most important themes in the Book of Revelation: worship.
 Daniel 12:1, Matthew 24:21.
 Both the Egyptian and the seven last plagues mention water turning to blood, darkness, sores and frogs.