Woe means “grief, anguish, affliction”; the three woes of Revelation are the final judgment God pronounces on the evil inhabitants of the earth in order to spur them to repentance (Revelation 9:20). The three woes are, indeed, a time of great anguish and affliction for those who have pledged their allegiance to the Antichrist during the end times.
The number 7 is significant in Revelation, and the three woes will come toward the end of the seven-year tribulation period right before the second coming of Christ. God’s judgments during the tribulation are pictured as seven seals, opened one at a time. The seventh seal reveals the seven trumpet judgments. The fifth, sixth, and seventh trumpets are called the three woes (Revelation 8:13).
The first woe is revealed after the fifth trumpet judgment. This woe is involves something like locusts that have the ability to sting like a scorpion (Revelation 9:3). Generally, these are not accepted as literal locusts because of their description and because they come from the Abyss and have a demonic overlord (Revelation 9:3, 7–8, 11). These creatures are permitted to harm only those people who do not have the “seal of God on their forehead” (Revelation 9:4). Those bearing God’s seal are the 144,000 (Revelation 7:3–4) or, possibly, all believers during that time (Ephesians 4:30). These demonic locusts are allowed to torment unbelievers for five months (Revelation 9:5) with painful stings. Although victims will long for death (Revelation 9:6), they will not be granted that release.
The second woe is revealed after the sixth trumpet judgment. This woe begins when a voice commands, “Release the four angels who are bound at the great river Euphrates” (Revelation 9:14). These four angels are demons who were cast from heaven along with Satan. God is right now keeping them imprisoned until the appointed time (Revelation 9:15; cf. Jude 1:6; 2 Peter 2:4). These angels and their armies, numbering two hundred million, are released to kill a third of mankind (Revelation 9:15–16).
After the second woe passes (Revelation 11:14), there comes a clear division in the book with the announcement from heaven, “The kingdom of the world has become the kingdom of our Lord and of his Christ” (Revelation 11:15). In other words, this final stage of judgment will be the end, and righteousness will be restored to the earth.
The third woe is revealed after the seventh trumpet judgment. This woe is parallel to the trumpet that sounds in Joel 2 and signals the consummation of God’s plan for the entire world. This third woe marks the finishing of God’s judgment on sin; it occupies the book of Revelation through the 19th chapter, when Christ’s Kingdom is established on earth. Incorporated within this third and final woe are the seven “bowls” of God’s wrath, described in Revelation 16:1–21. This series of judgments is the greatest horror the citizens of earth have ever seen. Jesus said, “If those days had not been cut short, no one would survive” (Matthew 24:22).
 Got Questions Ministries. (2010). Got Questions? Bible Questions Answered. Bellingham, WA: Logos Bible Software.