Revelation 8:1 When the Lamb opened the seventh seal, there was silence in heaven for about half an hour. Then I saw the seven angels who stand before God, and seven trumpets were given to them. And another angel came and stood at the altar with a golden censer, and he was given much incense to offer with the prayers of all the saints on the golden altar before the throne, and the smoke of the incense, with the prayers of the saints, rose before God from the hand of the angel. Then the angel took the censer and filled it with fire from the altar and threw it on the earth, and there were peals of thunder, rumblings, flashes of lightning, and an earthquake.
It would be natural to stand in silence when awaiting the outcome of the last seal being opened. Imagine seeing all the visions of 1-6 and knowing there are only 7 seals and the last one is now opened. What is to come from this last seal? John had just seen the sealing of the 144,000 and those who were clothed in white robes and was told by an elder that these were ones coming out of the great tribulation. Would the last seal be that of the New Heaven and Earth and the end of all earthly things? Would this last seal be the final judgment and consummation of the earthly and usher in the heavenly?
What John sees after this seal is opened is 7 angels, each given a trumpet. He sees an angel standing at a golden altar with a golden censer burning incense to offer with the prayers of all the saints. After this, the censer was filled with fire from the altar and threw it on earth. Upon this censer being thrown, there is a warning as if it is like a tornado siren warning. This warning sound came like thunder, rumbling, lightning, and an earthquake. Know this, there is something coming and it is not going to be good. There are warnings given by the Word of God and either heeded or rejected. During this time of great tribulation, as now, warnings from God should be taken very seriously.