The reasons for the Tribulation are twofold: first, to bring God's judgment upon a Christ-rejecting world; and secondly, to prepare a remnant of the Jewish people to meet their long-awaited Messiah. Revelation chapters 6-19, sometimes called Daniel's "seventieth week," concludes with the Battle of Armageddon and the return of Jesus Christ to the earth.

Rev 6:1 And I saw when the Lamb opened one of the seals, and I heard, as it were the noise of thunder, one of the four beasts saying, Come and see.
Rev 6:2 And I saw, and behold a white horse: and he that sat on him had a bow; and a crown was given unto him: and he went forth conquering, and to conquer.
Rev 6:3 And when he had opened the second seal, I heard the second beast say, Come and see.
Rev 6:4 And there went out another horse that was red: and power was given to him that sat thereon to take peace from the earth, and that they should kill one another: and there was given unto him a great sword.
Rev 6:5 And when he had opened the third seal, I heard the third beast say, Come and see. And I beheld, and lo a black horse; and he that sat on him had a pair of balances in his hand.
Rev 6:6 And I heard a voice in the midst of the four beasts say, A measure of wheat for a penny, and three measures of barley for a penny; and see thou hurt not the oil and the wine.
Rev 6:7 And when he had opened the fourth seal, I heard the voice of the fourth beast say, Come and see.
Rev 6:8 And I looked, and behold a pale horse: and his name that sat on him was Death, and Hell followed with him. And power was given unto them over the fourth part of the earth, to kill with sword, and with hunger, and with death, and with the beasts of the earth.
Rev 6:9 And when he had opened the fifth seal, I saw under the altar the souls of them that were slain for the word of God, and for the testimony which they held:
Rev 6:10 And they cried with a loud voice, saying, How long, O Lord, holy and true, dost thou not judge and avenge our blood on them that dwell on the earth?
Rev 6:11 And white robes were given unto every one of them; and it was said unto them, that they should rest yet for a little season, until their fellowservants also and their brethren, that should be killed as they were, should be fulfilled.
Rev 6:12 And I beheld when he had opened the sixth seal, and, lo, there was a great earthquake; and the sun became black as sackcloth of hair, and the moon became as blood;
Rev 6:13 And the stars of heaven fell unto the earth, even as a fig tree casteth her untimely figs, when she is shaken of a mighty wind.
Rev 6:14 And the heaven departed as a scroll when it is rolled together; and every mountain and island were moved out of their places.
Rev 6:15 And the kings of the earth, and the great men, and the rich men, and the chief captains, and the mighty men, and every bondman, and every free man, hid themselves in the dens and in the rocks of the mountains;
Rev 6:16 And said to the mountains and rocks, Fall on us, and hide us from the face of him that sitteth on the throne, and from the wrath of the Lamb:
Rev 6:17 For the great day of his wrath is come; and who shall be able to stand?

As Jesus opens the first seal, John hears one of the four living creatures give the order for the rider on the white horse to go forth. This first horseman is not Christ, but one who comes in His name. This evil personage is known by many names, but primarily as the Antichrist or Beast. He has a bow but no arrows, indicating that he shall "come in peaceably, and obtain the kingdom by flatteries" (Dan. 11:21, 24). He will rise to power through the voluntary alliance of ten western European nations uniting under a one-world government.

As the "prince that shall come" (Dan. 9:26), he will lead Israel into signing an international peace pact which Isaiah describes as a "covenant with death, and with hell" (Isa. 28:15, 18). This treaty will guarantee the Jewish nation not only a time of peace and security, but also an occasion to rebuild their temple.

Next John sees the second seal opened and the red horse rider summoned forth. Red is the color of bloodshed and war. Peace will be short-lived, as somewhere near the midst of the Tribulation week Russia and her Muslim allies will sweep down upon the mountains of the small and unsuspecting nation of Israel. Through a series of God's judgments, the northern army is destroyed leaving only a sixth part. The destruction will be so great that it will take seven years to burn the weapons and seven months to bury the dead. This deadly war begins a series of conflicts that escalate until all the nations of the world are drawn into the blood-soaked Battle of Armageddon.

With the defeat of the Russian armies, the Antichrist uses this opportunity to seize world control. He then breaks his agreement with Israel and establishes himself in the newly rebuilt temple proclaiming himself God.

The third seal beckons the black horse rider. After war comes famine and economic disaster. The majority of the world's population will face starvation during this period on an unprecedented scale. Gold, silver, and paper currency will become useless as they're soon replaced by a monetary system controlled by the Beast. Food will be rationed and a person will find himself working all day just to feed himself. Yet the rich will get richer having access to luxuries that are denied to the common man.

After this the fourth seal is opened and John sees a pale horse whose rider is named Death. He is followed closely by Hell (hades). Death claims the body while Hades devours the soul and spirit. This lethal judgment will claim only unbelievers who are killed through God's "four sore judgments" of war, famine, plague, and wild beasts. Twenty-five percent of the world's population will perish from this one calamity alone!

The fifth seal reveals the martyred saints of the first three and one-half years. They are now under the heavenly altar after being murdered for their faith in Jesus Christ. They are given white robes symbolizing the righeousness of God. Their souls cry out for vengeance, but they're told they must be patient and wait for others who will be killed during the remainder of the Great Tribulation.

A catastrophic earthquake that will usher in the wrath of God and the last half of the Tribulation period announces the sixth seal. The sun, moon, and stars are effected (notice the word "as") and every mountain and island on earth shaken. I believe these will be literal judgments poured out on a Christ-rejecting world. Men will realize during this time that the end is near, but they would rather escape through death than call on God in repentance.

Rev 7:1 And after these things I saw four angels standing on the four corners of the earth, holding the four winds of the earth, that the wind should not blow on the earth, nor on the sea, nor on any tree.
Rev 7:2 And I saw another angel ascending from the east, having the seal of the living God: and he cried with a loud voice to the four angels, to whom it was given to hurt the earth and the sea,
Rev 7:3 Saying, Hurt not the earth, neither the sea, nor the trees, till we have sealed the servants of our God in their foreheads.
Rev 7:4 And I heard the number of them which were sealed: and there were sealed an hundred and forty and four thousand of all the tribes of the children of Israel.
Rev 7:5 Of the tribe of Juda were sealed twelve thousand. Of the tribe of Reuben were sealed twelve thousand. Of the tribe of Gad were sealed twelve thousand.
Rev 7:6 Of the tribe of Aser were sealed twelve thousand. Of the tribe of Nepthalim were sealed twelve thousand. Of the tribe of Manasses were sealed twelve thousand.
Rev 7:7 Of the tribe of Simeon were sealed twelve thousand. Of the tribe of Levi were sealed twelve thousand. Of the tribe of Issachar were sealed twelve thousand.
Rev 7:8 Of the tribe of Zabulon were sealed twelve thousand. Of the tribe of Joseph were sealed twelve thousand. Of the tribe of Benjamin were sealed twelve thousand.
Rev 7:9 After this I beheld, and, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the throne, and before the Lamb, clothed with white robes, and palms in their hands;
Rev 7:10 And cried with a loud voice, saying, Salvation to our God which sitteth upon the throne, and unto the Lamb.
Rev 7:11 And all the angels stood round about the throne, and about the elders and the four beasts, and fell before the throne on their faces, and worshipped God,
Rev 7:12 Saying, Amen: Blessing, and glory, and wisdom, and thanksgiving, and honour, and power, and might, be unto our God for ever and ever. Amen. Rev 7:13 And one of the elders answered, saying unto me, What are these which are arrayed in white robes? and whence came they?
Rev 7:14 And I said unto him, Sir, thou knowest. And he said to me, These are they which came out of great tribulation, and have washed their robes, and made them white in the blood of the Lamb.
Rev 7:15 Therefore are they before the throne of God, and serve him day and night in his temple: and he that sitteth on the throne shall dwell among them.
Rev 7:16 They shall hunger no more, neither thirst any more; neither shall the sun light on them, nor any heat.
Rev 7:17 For the Lamb which is in the midst of the throne shall feed them, and shall lead them unto living fountains of waters: and God shall wipe away all tears from their eyes.

Between the sixth and seventh seal is an interval concerning two groups of people who will be on earth during this time. The first company is the 144,000 Jewish "evangelists" who will preach the gospel of the kingdom (Matt. 24:14) to the whole world. Many believe that the church must preach the gospel to every nation on earth before the Lord can return, but when Jesus spoke of "the end" in the Gospel of Matthew, He was speaking of the end of the age or Second Coming, not the Rapture that could occur at any moment.

God will seal twelve thousand of these saved Israelites from each of the twelve tribes. Just as Noah and his family were preserved safely through the flood; these 144,000 Jewish believers will also be protected through the Tribulation hour.

John then sees a second group that is standing before the heavenly throne. They are the great blood-washed multitude of Gentile believers who've been martyred for their faith. They have come out of the Great Tribulation and have washed their robes in the blood of the Lamb. Their white robes symbolize righteousness and the palms are significant of the victory they've won over the Beast and the false prophet.

They attribute their salvation to God and the Lamb and are a direct result of the ministry of the 144,000 Jewish missionaries who've risked their lives to proclaim Christ to all the nations of the world. Their sufferings and trials being over, these believers now serve God forever in continual bliss.