Correct.  Keep up the good work!

"And I saw, as it were, a sea of glass mixed with fire, and those who had come off victorious from the beast and from his image and from the number of his name, standing on the sea of glass, holding harps of God."  Revelation 15:2  (NAS)

Although Satan had tried (through the two beasts) to get everyone to worship the beast and his image and to be marked with the mark of the beast...Satan failed to get everyone.  Those who had come off victorious from the beast and from his image were now to receive their reward (as we read earlier, these are the victorious who were sealed with the name of God and the Lamb).

In the midst of persecution and false teaching, what a great comfort this must have been to those who were remaining faithful to God...and to those whose loved ones had lost their lives because of their witness to Jesus Christ.

The sea of glass before the throne of God and the Lamb:

These who were victorious were standing on the sea of glass.  This appears to be the  same identical picture that we see in the previous scene in Revelation 4:6 and Revelation chapter 7:

and before the throne there was, as it were, a sea of glass like crystal; and in the center and around the throne, four living creatures full of eyes in front and behind. Revelation 4:6 (NAS)

After these things I looked, and behold, a great multitude, which no one could count, from every nation and all tribes and peoples and tongues, standing before the throne and before the Lamb, clothed in white robes, and palm branches were in their hands; Revelation 7:9 (NAS)

The sea of glass is mixed with fire:

Revelation 15:2 says that the sea of glass was mixed with fire.

The victorious are standing on the sea of glass:

Those that were victorious (those who did not worship the beast and the image of the beast, and did not receive the mark of the beast on their foreheads or hands) were seen by John in the vision standing on the sea of glass before the throne of God and the Lamb.

The victorious sing:

"And they sang the song of Moses the bond-servant of God and the song of the Lamb, saying, "Great and marvelous are Thy works, O Lord God, the Almighty; Righteous and true are Thy ways, Thou King of the nations.  Who will not fear, O Lord, and glorify Thy name?  For Thou alone art holy; for all the nations will come and worship before Thee, for Thy righteous acts have been revealed." Revelation 15:2-4 (NAS)

Seven angels and seven bowls:

After these things I looked, and the temple of the tabernacle of testimony in heaven was opened, and the seven angels who had the seven plagues came out of the temple, clothed in linen, clean and bright, and girded around their breasts with golden girdles.  And one of the four living creatures gave to the seven angels seven golden bowls full of the wrath of God, who lives forever and ever.  And the temple was filled with smoke from the glory of God and from His power; and no one was able to enter the temple until the seven plagues of the seven angels were finished"  Revelation 15:5-8 (NAS)

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