1 Then I saw in heaven another marvellous event of great significance. Seven angels were holding the seven last plagues, which would bring God’s wrath to completion.  2-3 I saw before me what seemed to be a glass 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: 4 “Great and marvellous are your works, O Lord God, the Almighty. Just and true are your ways, O King of the nations. Who will not fear you, 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.”

5-8 Then I looked and saw that the Temple in heaven, God’s Tabernacle, was thrown wide open. The seven angels who were holding the seven plagues came out of the Temple. They were clothed in spotless white linen with gold sashes across their chests. Then one of the four living beings handed each of the seven angels a gold bowl filled with the wrath of God, who lives forever and ever.  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. Revelation 15:1 -8 New Living Translation (English Standard Version link)

One of the most significant events in the Old Testament was when God sent devastating plagues on the land of Egypt until they let His people go. When the Egyptians pursued them again, God drowned their army in the Red Sea. After that victory the people sang 'the song of Moses' to God, and some of the words were these: “I will sing to the Lord for He is highly exalted. Your right hand, Lord, shattered the enemy. In the greatness of your majesty you threw down those who opposed you and unleashed your burning anger;  it consumed them like stubble. Who is like you - majestic in holiness, awesome in glory, working wonders? In your unfailing love you will lead the people you have redeemed. In your strength you will guide them to your holy dwelling. The nations will hear and tremble!” (Exodus 15)

In today's part of John's vision we see that those who were victorious over the beast were also singing 'the song of Moses'. In other words, the same God who gave Israel victory over the Egyptians now gives victory to Christians through Jesus (the Lamb) over Satan's schemes in the world. (vs 3) What are the things their song tell us about God? (vs 4)

God is seen to be highly exalted over all the nations of the world. He is recognized as being holy and perfectly just in all His ways, and is worshiped by people from all nations. In fact, the day will dawn when the nations will have no option but to acknowledge that Jesus is Lord. Meanwhile, that song expressed what believers who had gone to heaven thought of God as they gazed on His glory. So heaven was filled with singing - but what was about to happen on earth? (vs 5-8)

The time had come when angels were going to pour out bowls that were filled with God's wrath upon the world. In earlier chapters of Revelation John had seen how seven angels had blown trumpets. Trumpets were often used to warn of danger. And at the sound of those trumpets smaller plagues had fallen on the earth. (Just as some of the earlier plagues God sent on the Egyptians were lesser ones, and intended to warn them). But, like the Egyptians, the people in the world still gave their allegiance to Satan and fought against God, so now the final showdown had arrived. What John wrote in his gospel was now coming to pass. In John 3:36 he’d said: “Whoever believes in God's Son has eternal life - but whoever rejects the Son will not see life, for God’s wrath remains on them.” There's a hymn that sums up today's thoughts well. I've adapted it slightly but it says::

“When this passing world is done, and when has set the radiant sun. When I stand with Christ on high, gazing on my life gone by; Then, Lord, will I fully know – not till then, how much I owe!”