Seven angels and a sea of glass
Rev 15:1 And I saw another sign in heaven, great and marvellous, seven angels having the seven last plagues; for in them is filled up the wrath of God.
We are going back before the end, to see more of the wrath of God poured out upon the ungodly; this time seven angels with seven vials of plagues. We have seen the seal judgments in Rev. 6, The trumpet judgments in Rev. 8 and 9, Now the final vial or bowl judgments. The Revelation is not always in order. We saw the end of the antichrist in Rev. 14 and also in Rev 6. This chapter shows the ultimate Exodus, the freedom of God's people from a sinful and persecuting world.
Rev 15:2 And I saw as it were a sea of glass mingled with fire: and them 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.
The sea of glass was the presence and glory of God. It was holy ground.
Rev 4:6 And before the throne there was a sea of glass like unto crystal...
The sea could also remind us of the Red Sea deliverance of God's people.
Fire represents the judgment of God.
Mat 3:12 Whose fan is in his hand, and he will thoroughly purge his floor, and gather his wheat into the garner; but he will burn up the chaff with unquenchable fire.
Those standing on the sea of glass were those who came out of the tribulation, them that had gotten the victory over the beast, and over his image, and over his mark, and over the number of his name, they are the martyrs described in Rev 7.
Rev 7:9 After this I beheld, and, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the throne, and before the Lamb, clothed with white robes, and palms in their hands;
Rev 7:10 And cried with a loud voice, saying, Salvation to our God which sitteth upon the throne, and unto the Lamb.
They were worshipping God with harps and music, as did the 24 elders before the throne of God.
Rev 5:8 And when he had taken the book, the four beasts and four and twenty elders fell down before the Lamb, having every one of them harps, and golden vials full of odours, which are the prayers of saints.
Rev 5:9 And they sung a new song, saying, Thou art worthy to take the book, and to open the seals thereof...
Rev 14:2 And I heard a voice from heaven, as the voice of many waters, and as the voice of a great thunder: and I heard the voice of harpers harping with their harps:
Rev 14:3 And they sung as it were a new song before the throne...
These two earlier references to harpists, said that they sang a new song. We are to sing new songs to glorify God, from the heart. The multitude on the sea of glass sing an old song, (I like the old hymns); the song of Moses, a victory song.
Rev 15:3 And they sing the song of Moses the servant of God, and the song of the Lamb, saying, Great and marvellous are thy works, Lord God Almighty; just and true are thy ways, thou King of saints.
Rev 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; for thy judgments are made manifest.
A new title to the old song of Moses; the song of Moses and the song of the Lamb. The old covenant and the new together in victory; law and grace. This song of worship and praise is all about God, they sang songs to glorify him. Let us sing praises to Him, it's not about us Lord; you are to be glorified.