The seventh seal is used for the introduction of the seven trumpets.
1 When He opened the seventh seal, there was silence in heaven for about half an hour.
The phrase “half an hour” could refer to 6 months of calm from the barrages of the prior 6 seals
2 Then I saw the seven angels who stand in the presence of God; seven trumpets were given to them.
The angels were given the trumpets and were on standby, waiting for God’s command to blow them. The trumpets are going to be worse than the seals. Each stage of judgments gets more intense.
3 Another angel, with a gold incense burner, came and stood at the altar. He was given a large amount of incense to offer with the prayers of all the saints on the gold altar in front of the throne.
Most likely these prayers refer to the Christians who are going through the great tribulation. All of their prayers for help are brought by an angel to the throne of God.
4 The smoke of the incense, with the prayers of the saints, went up in the presence of God from the angel’s hand.
Keywords: smoke, incense, and prayers all mean the same. The prayers of the saints fill God’s throne and as incense is pleasant to one’s nostrils so prayers are to God’s ears.
5 The angel took the incense burner, filled it with fire from the altar, and hurled it to the earth; there were rumblings of thunder, flashes of lightning, and an earthquake.
God responded to the prayers of the saints by bringing severe judgment upon those on the earth who were persecuting them.