Read or listen The Book of Revelation, chapter 15 online (ESV, YouVersion)

In Heaven 15:1-8

In verse 1, John begins to describe the vision of the seven bowls of God’s wrath. He sees seven angels and they are ready to carry out the seven last plagues that will afflict the world. In the next verse, however, the vision of the bowls of wrath does not continue, but John is shown another vision. He sees heaven and there “those who had conquered the beast and its image and the number of its name". They sing the song of Moses and the song of the Lamb, giving glory to God, to whom all glory belongs.

Perhaps the reader of Revelation wonders why this second vision is shown now, even though it should have begun with the description of the pouring out of the bowls of wrath. The vision from heaven has not come here by accident. As in other passages, the Book of Revelation wants to encourage God's people to endure the pressure that exists in this world. That is also the purpose of this vision from heaven.

It has been said above that the beast will gain great power in the world, persecute God's people, and try to destroy the Church. And the shocking description of the seven last plagues is about to begin. In the difficulties that the Book of Revelation describes and in which God's church has to live, God's own may wonder whether it is worth living as a child of God at all, since it does not bring an easy life. To this the vision from heaven answers: Even then it will be worth it, because only as a child of God can you get to where it is good to be. You must not give up, even if you get into trouble for the name of Jesus. If you abandon the faith, you will not get to where the song of Moses and the Lamb is sung. Instead, you will be among those who were described in a terrible way at the end of the previous chapter. The vision from heaven wants to say this before we begin to tell about the last plagues.

Those who have reached heaven are said to sing the song of Moses and the Lamb. This reminds us that among those who have reached heaven are the saints of both the old and new covenants. Moses refers to the old covenant and the Lamb to the new. All of God’s people who have lived in this world will one day be one group and sing praises to God.

In heaven, God is praised for having judged the world. Many people find this cruel and wonder how those who have reached heaven can thank God for this. After all, God’s judgment means that many people will be subjected to the worst possible destruction. This is true, but God’s judgment is still just, and God is praised in heaven for it. In heaven, we see God’s immense holiness and realize that this is exactly what had to happen.

It is certainly a matter of wonder and thanksgiving that God delayed His judgment for so long. Even though he saw the wickedness of people and it fought against his holiness, he gave the world more time of grace. He waited patiently for as many as possible to get to where God is and where it is therefore so good to be.

The happiness of heaven is indicated by the mention of the crystal sea. In this world, there are fierce storms that make the world shake violently. In heaven, there are no such storms. The sea in heaven is as smooth as the surface of crystal glass.

Then John sees the seven angels in more detail. They resemble the one they serve (see Revelation 1:13). They receive bowls from a being that John has seen before (Revelation 4:6-8), and the bowls are said to be full of the wrath of God. So it is a time of judgment, and during the execution of judgment no one is allowed to approach God in the temple.