7 Trumpets of REVELATION SERIES: SEVENTH Trumpet

Then the seventh angel sounded: 

And there were loud voices in heaven, saying: "The kingdoms of this world have become the kingdoms of our Lord and of His Christ, and He shall reign forever and ever!"  

And the twenty-four elders who sat before God on their thrones fell on their faces and worshiped God, saying: "We give You thanks, O Lord God Almighty, the One who is and who was and who is to come, because You have taken Your great power and reigned.
Revelation 11:15-17

O Lord God Almighty, which art - This gives a proper view of God in His eternity: all times are here comprehended, the present, the past, and the future. This is the infinitude of God.

Observe, 1. The manner of their adorations: they rose from their seats, and fell upon their faces, and worshipped God; they did it with reverence and humility. 

2. The matter of their adorations. 

(a) They thankfully recognize the right of our God and Saviour to rule and reign over all the world: The kingdoms of this world have become the kingdoms of our Lord and of His Christ. They were always so in title, both by creation and purchase. 

(b) They thankfully observe His actual possession of them, and reign over them; they give Him thanks because He had taken to Him His great power, asserted His rights, exerted His power, and so turned title into possession. 

(c) They rejoice that this His reign shall never end: none shall ever wrest the sceptre out of His hand.

Probation closes when the seventh trumpet is about to sound. At that moment, Jesus will receive the kingdom from His Father. Then the time of trouble will ensue followed by the blowing of the seventh trumpet when Jesus comes to take His people home.
The Jamieson, Fausset and Brown Commentary is on target:

“The seventh trumpet, like the seventh seal and seventh vial, being the consummation, is accompanied differently from the preceding six: not the consequences on earth, but those IN HEAVEN, are described, the great voices and thanksgiving of the 24 elders in heaven, as the half-hour's silence in heaven at the seventh seal, and the voice out of the temple in heaven, ‘It is done,’ at the seventh vial. 

Thus, the seven seals, seven trumpets, and seven vials, are not consecutive, but parallel, ending in the same consummation. 

They, from distinct stand-points, unfold God's plans for bringing about the grand end, under three aspects, 

mutually complementing each other.”

When the angels are released in the sixth trumpet, probation has not closed because probation does not close until the seventh angel is about to sound at the very end of the sixth trumpet. This is a vital point.
We must link Revelation 17:14 [These shall make war with the Lamb, and the Lamb shall overcome them: for He is Lord of lords, and King of kings: and they that are with Him are called, and chosen, and faithful.] with Revelation 19:11 [And I saw heaven

opened, and behold a white horse; and He that sat upon him was called Faithful and True, and in righteousness He doth judge and make war.] where Jesus bears the title ‘KING OF KINGS AND LORD OF LORDS. 

This means that Revelation 11:15 [And the seventh angel sounded; and there were great voices in heaven, saying, The kingdoms of this world are become the kingdoms of our Lord, and of His Christ; and He shall reign for ever and ever.] is repeated again in Revelation 17:14 [see verse above] and Revelation 19:16. [And He hath on His vesture and on His thigh a name written, KING OF KINGS, AND LORD OF LORDS.] 

--This proves that we cannot read Revelation as a continuous flow but rather full of recapitulations and repetitions.

Revelation 11:17 [Saying, We give thee thanks, O Lord God Almighty, which art, and wast, and art to come; because Thou hast taken to Thee Thy great power, and hast reigned.] actually concludes the seventh trumpet. 

Revelation 11:18 [And the nations were angry, and thy wrath is come, and the time of the dead, that they should be judged, and that thou shouldest give reward unto thy servants the prophets, and to the saints, and them that fear thy name, small and great; and shouldest destroy them which destroy the earth.] then introduces and summarizes the main events of the rest of the book.

This verse contains five key points of time that form the structure of the rest of the book:
Revelation 12-14 - The Nations were angry
Revelation 15-19 - Your wrath has come
Revelation 20:4, 11, 12 - The time to judge the dead
Revelation 19:11-21; 22:12 - The time to reward your servants
Revelation 20:14, 15 - Destroy those who destroy the earth
Thou Shouldst Give Reward Unto Thy Servants the Prophets: These will enter upon their reward at the second coming of Christ, for He brings their reward with Him. (Matthew 16: 27; Revelation 22: 12).

Drawn/taken from the book Daniel & Revelation by Uriah Smith---Study Guide by Stephen Bohr---Sermon by Walter Veith---Commentaries from Matthew Henry/Adam Clark---Revelation Made Clear