Revelation 6:17

for the great day of His wrath is come, and who shall be able to stand?

There is an obvious agreement here with Matthew 24:1, where the Lord speaks of the signs and wonders which would precede the Judgment and the end of the world. For although not all the scenes of Judgment are here included, yet the most important ones stand out plainly: And I saw when He opened the sixth seal, and a great earthquake happened, and the sun became black as sackcloth, and the full moon became like blood, and the stars of heaven fell to the earth, as a fig-tree casts her figs when shaken by a mighty wind. With the opening of the sixth seal by the Lamb the special signs which should usher in the last day were enacted before the eyes of John. There was a great and terrible earthquake, Luke 21:11; the sun and the moon were darkened, Joel 2:31; Matthew 24:29; the stars fell down from the firmament, Matthew 24:29; all nature was in an uproar, the universe was disintegrating. And still more: And the heaven was removed like a rolled-up scroll, and every mountain and island was displaced from its location. The firmament of the heavens, apparently secure for eternity, will not escape in the last great disturbances of the universe. Just as a roll of parchment is rolled up and laid aside, so the firmament will be removed. And at the same time the solid mountains that have withstood the storms of centuries, and the islands that have defied the billows of untold hurricanes, will be displaced, set aside, as no longer needed.

What effect this would have on the people of the world is also shown: And the kings of the earth and the mighty ones and the generals and the wealthy and the strong ones and every slave and freeman hid themselves in the caves and in the rocks of the mountains, and said to the mountains and the rocks, Fall upon us and hide us from the face of Him that sits upon the throne, and from the wrath of the Lamb; for the great day of Their wrath has come, and who is able to stand? Here the terror and despair of the enemies of the Lord, of which He Himself has prophesied, is delineated. On the last great day the defiant authority of the proud rulers of the world, of kings and mighty ones and generals, will sink into the dust, and they will seek respite and deliverance like the lowest of their subjects. Then all the wealth of the earth will not buy salvation, and the strength of a thousand oxen will not effect escape. Then the slaves and the freemen will be on the same level, and no man will think of social distinctions. And they all, filled with unspeakable dread, will cower in abject terror and fly to the crags and caves of the mountains, vainly hoping to find a spot where the angry glances of the holy God will not strike them, where the wrath of the Lamb, whose sacrifice they rejected in their unbelief, will not find them. That is what the breaking of the sixth seal uncovered: the terrors of the godless world on the day of the Judgment of God. Only the Christians, certain of the atonement of Christ which they have accepted by faith, will rejoice on that day, knowing that their redemption is nigh.

Summary

As the Lamb opens six of the seven seals on the scroll in. the hand of God, some of the tribulations and persecutions of the last days of the world are exhibited, culminating in the terrors of the last day, but also the deliverance of the martyrs, with the promise that God would vindicate his holiness.