Then I saw in heaven another significant event, and it was great and marvelous. Seven angels were holding the seven last plagues, which would bring God's wrath to completion.
I saw before me what seemed to be a crystal sea mixed with fire. And on it stood all the people who had been victorious over the beast and his statue and the number representing his name. They were all holding harps that God had given them.
And they were singing the song of Moses, the servant of God, and the song of the Lamb: "Great and marvelous are your actions, Lord God Almighty. Just and true are your ways, O King of the nations.
References for Revelation 15:3
Who will not fear, O Lord, and glorify your name? For you alone are holy. All nations will come and worship before you, for your righteous deeds have been revealed."
Then I looked and saw that the Temple in heaven, God's Tabernacle, was thrown wide open!
The seven angels who were holding the bowls of the seven plagues came from the Temple, clothed in spotless white linen with gold belts across their chests.
References for Revelation 15:6
And one of the four living beings handed each of the seven angels a gold bowl filled with the terrible wrath of God, who lives forever and forever.
The Temple was filled with smoke from God's glory and power. No one could enter the Temple until the seven angels had completed pouring out the seven plagues.