The seventh trumpet is the conclusion of the eternal economy of the processed Triune God.
The seventh trumpet is the finishing of the mystery of God. Revelation 10:7 says, "But in the days of the voice of the seventh angel when he is about to trumpet, the mystery of God also is finished, as He announced the good news to His own slaves the prophets."
The seventh trumpet closes the present age of mystery. Daniel 9:24 speaks of the seventy weeks, which were apportioned out to "seal up vision and prophet." To seal up vision and prophet is to close the age of mystery.
The seventh trumpet will bring in the coming age of the kingdom and the eternal age of the new heaven and new earth. It comprises all the things from the end of the great tribulation to eternity future.
The seventh trumpet includes the coming of the eternal kingdom of God and of Christ, in which He shall reign forever and ever (Rev. 11:15-17).
Christ shall reign first in the millennium, the one thousand years in the kingdom age.
After that, Christ shall reign forever in the new heaven and new earth with the New Jerusalem as its center.
The seventh trumpet will include the judgment of the dead (Rev. 11:18b) to decide who among the dead should participate in the resurrection of life before the millennium and who should be left to participate in the resurrection of judgment after the millennium (John 5:28-29; Dan. 12:2).