Unlike the other five seals, the text of the sixth seal is straightforward and uncomplicated. Only a few of the details in the description require more than a brief comment in explanation. Far more important to understanding this seal as a judgment is the effect the signs have on the people of the earth.
The seal opens with "a great earthquake" (Revelation 6:12), a common indicator of God appearing (see Judges 5:4; Psalm 68:8; 77:18; 97:4; Habakkuk 3:10; Haggai 2:6-7), working out His purpose (see Exodus 19:18; Matthew 27:51-54; 28:2; Acts 16:26), and/or striking out in displeasure and judgment. In terms of anger and punishment, God caused an earthquake to open the ground in the wilderness and swallow Korah and his fellow rebels (Numbers 16:31-32). In Psalm 18:7, David writes, "Then the earth shook and trembled; the foundations of the hills also quaked and were shaken, because He was angry" (see Isaiah 5:25; Nahum 1:2-5). God prophesies in Isaiah 13:11, 13, "I will punish the world for its evil, and the wicked for their iniquity. . . . Therefore I will shake the heavens, and the earth will move out of her place, in the wrath of the LORD of hosts, and in the day of His fierce anger."
Earthquakes occur frequently in Revelation, of which this one is the first. Seismic activity accompanies the seventh seal (Revelation 8:5), the resurrection of the Two Witnesses (11:13), the seventh trumpet (11:19), and the seventh bowl or vial (KJV) of God's wrath (16:18). Evidently, massive earthquakes—the kind that strikes dread and panic into every soul caught in them—will frequently punctuate the Day of the Lord.
Certainly, the heavenly signs that occur in tandem with the great temblor are astounding, especially if all of them should occur within a short span of time. Joel 2:30-31 describes the same event: "And I will show wonders in the heavens and in the earth: blood and fire and pillars of smoke. The sun shall be turned into darkness, and the moon into blood, before the coming of the great and terrible day of the LORD." In the Olivet Prophecy, Jesus repeats the warning: "Immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light; the stars will fall from heaven, and the powers of the heavens will be shaken" (Matthew 24:29; Mark 13:24-25). Luke's rendition adds a few details:
And there will be signs in the sun, in the moon, and in the stars; and on the earth distress of nations, with perplexity, the sea and the waves roaring; men's hearts failing them from fear and the expectation of those things which are coming on the earth, for the powers of heaven will be shaken. (Luke 21:25-26)
The Sun Darkened: John describes the darkness of the sun as "black as sackcloth of hair" (Revelation 6:12), comparing it to the black goat hair used to make sackcloth and tents in his day. This may depict a solar eclipse or possibly a massive dust storm caused by a volcanic explosion. The Ninth Plague covered Egypt with a "darkness which may even be felt," a "thick darkness" (Exodus 10:21-22), and perhaps God will repeat it on an even grander scale. Whatever the case, visibility will be severely limited, even during the daylight hours.
The Moon Like Blood: This chilling sight presages calamity and death, particularly in war, as in the color of the second horse (Revelation 6:4). Sometimes lunar discoloration occurs naturally when unusual amounts of dust are suspended in the atmosphere, particularly after a volcanic eruption or an earthquake. Incidentally, many manuscripts read "full moon" rather than simply "moon."
The Stars Fall: John's imagery reflects countless late figs blown down by the violent winter wind (verse 13). This seems most likely to predict a meteor shower of immense proportions, possibly containing larger-than-normal meteorites, thus increasing the effect and making it seem as if the stars themselves are falling. Because stars are a biblical symbol of angels, some have suggested that this verse parallels Revelation 12:7-10, the casting out of Satan and his demons from heaven. However, for this to have any credence, the concurrent celestial events must also be taken symbolically.
The Sky Recedes: Of these four wonders, this event is the most puzzling (Revelation 6:14). The apostle compares it to a scroll rolling up, or we might think of it in terms of opening a spring-loaded window blind. Joseph A. Seiss, in his The Apocalypse: Exposition of the Book of Revelation, comments: "Great, massive, rotary motion in the whole visible expanse, is signified, as if it were folding itself up to pass away forever." Perhaps John saw clouds building to thunderheads, roiling, and flying at breakneck speed across the expanse of the sky. Such turbulence could make an observer on the ground think the sky was splitting apart. Isaiah 34:4 describes the Day of the Lord similarly.
The Mountains and Islands Move: As a result of the great convulsion of the earth, massive land transformations occur, shifting mountains on land and undersea. Obviously, such a violent shaking will create unprecedented destruction and loss of life. As the conclusion of the sixth seal's disturbances, this displacement of terra firma is the calamity that most terrifies earth's inhabitants. Suddenly, nothing is stable—not even the earth under their feet!
Finally, God has their attention!