The second half of the final seven years (the seventieth "seven") is the great tribulation: the Antichrist rules and the suffering falls on God's people. Revelation 13 showed the second beast making an image of the first and killing all who will not bow to it.
In the first half, the two witnesses preached and some 144,000 people were prepared. At the midpoint the Antichrist stops the sacrifice and offering, kills the two witnesses, and his kingdom begins.
The angels' message is carried by people
An angel flies in mid-heaven with the everlasting gospel for every nation, kindred, tongue and people, and cries:
Fear God, and give glory to him; for the hour of his judgment is come…
— Revelation 14:7
Angels do not preach the gospel; that work belongs to people, so this message comes through human voices.
After the half hour the church, the bride, has been taken up, and the two witnesses are dead. That leaves the 144,000, who "follow the Lamb whithersoever he goeth" (Revelation 14:4): not behind a lamb, but as the Lord Jesus leads them by the Spirit. They announce that judgement has come: when the seventieth seven ends, the Lord comes down to judge, and the thousand-year kingdom follows. They carry the message to every nation, perhaps by returning to the lands the gathered Jews originally came from.
The second message: Babylon is fallen
Babylon is fallen, is fallen, that great city, because she made all nations drink of the wine of the wrath of her fornication.
— Revelation 14:8
This is the woman of Revelation 17. The two witnesses will have taught, and the 144,000 repeat, that Israel should never have joined the seven-year covenant (karaar), whose head will be a man in the office of Pope, trusted as a good man. At the right time Satan will enter him, as he entered Judas, one of the twelve, and the witnesses will see at once that he is wrong.
The nations "drink" by joining the new body one by one, like members of the United Nations. With such power, and Satan within him, he can forbid anyone to buy or sell unless they bow to him.
At the midpoint he stops the sacrifices in Jerusalem, where a mosque stands today; a temple will be built under the covenant's terms, perhaps within the half hour. Then, as 2 Thessalonians 2:3–4 says, the man of sin sits in the temple of God, showing himself that he is God.
The third message: do not take the mark
The third angel warns that whoever worships the beast and his image and takes his mark will drink the wine of God's wrath (Revelation 14:9–11). For three and a half years they can buy and sell; then God's wrath falls, in the period called the Day of the Lord, and plagues kill them. After the thousand years they are cast into the lake of fire and brimstone.
Here is the patience of the saints: here are they that keep the commandments of God, and the faith of Jesus.
— Revelation 14:12
That patience will be tested: refusing the mark means death at the hands of the second beast, taking it means God's wrath. Those killed join the martyrs of the fifth seal (those killed in Hitler's time), who were told to rest until others like them were killed; then all are rewarded together. Those who have died in the Lord up to now are blessed (14:13): they are spared this terror.
The woman, the child and the dragon
Revelation 12:1–5 shows a woman clothed with the sun, the moon under her feet and a crown of twelve stars, who bears a son to rule all nations with a rod of iron. That rod belongs to Christ (Psalm 2:7–9; Revelation 19:15).
The woman is not Mary: she flees into the wilderness for 1,260 days (12:6), but Mary lived in the disciple John's house (John 19:25–27). She is Israel, the nation Jesus was born from. The twelve stars are the twelve tribes; the sun is the light of Christ in the new covenant, and the moon under her feet the old covenant, now ended.
The dragon with seven heads and ten horns is Rome again, the empire set on seven hills, which tried to destroy the child; he was caught up to God at the ascension.
In the great tribulation Israel flees to a place God has prepared, to be nourished "a time, and times, and half a time" (12:14): 1,260 days. The "two wings of a great eagle" are the two witnesses (the eagle stands for prophets), who tell Israel where to go. The 144,000 go wherever the Spirit leads.
Satan cast down, and the pursuit of Israel
In the war in heaven (Revelation 12:7–12), Michael fights the dragon, "that old serpent, called the Devil, and Satan", who is cast down to the earth. He had accused God's people before God day and night, and he does so still. Knowing his time is short, he is furious and works by inspiring people to bring chaos on the earth.
He then pursues the woman through the Antichrist, who sends armies after those who heard the two witnesses. While the witnesses' bodies lie for three and a half days, the 144,000 vanish into their own countries, and the rest of Israel heads for the prepared place, with a "flood" of people sent after them. The earth swallows the flood; we cannot tell whether that is literal or spiritual.
Then the dragon makes war with "the remnant of her seed, which keep the commandments of God, and have the testimony of Jesus Christ" (12:17): Jews, who keep the law, and those who believed through the two witnesses. Israel thus appears in three groups: the 144,000, led by the Spirit; the woman, who flees as directed; and the remnant, who can do neither and try to hide.
Seventy-five extra days
Daniel 12:11–12 gives 1,290 and 1,335 days: add 30 and then 45 to the woman's 1,260. These 75 extra days are the Day of the Lord, when God's wrath is poured out on the earth.
Takeaway
The three angels call people to fear God, to refuse any share in Babylon or the mark, and to endure. Believers can be sure that Satan, who accuses them before God day and night, will be cast down.