During the seven year period following the Rapture of Christians from the earth, God will pour out His judgment upon the earth and those left who have rejected His Son as their Lord and Savior. The first of these judgments are known as the "seal judgments". In the Book of Revelation, the Bible describes what will happen after each seal is broken.
And I saw in the right hand of him that sat on the throne a book written within and on the backside, sealed with seven seals. (Revelation 5:1)
The First Seal
The Four Horsemen
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. 6:1)
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. 6:2)
The Second Seal
3 - And when he had opened the second seal, I heard the second beast say, Come and see.
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. 6:3-4)
The Third Seal
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.
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. 6:5-6)
The Fourth Seal
7 - And when he had opened the fourth seal, I heard the voice of the fourth beast say, Come and see.
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. 6:7-8)
4 - DEATH
3 - FAMINE
2 - WAR
The Fifth Seal
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:
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?
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. 6:9-11)
Judgment/Vengeance
"Judgment is mine, sayeth the Lord."
The Sixth Seal
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;
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.
14 - And the heaven departed as a scroll when it is rolled together; and every mountain and island were moved out of their places.
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;
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:
17 - For the great day of his wrath is come; and who shall be able to
stand?
(Rev. 6:12-17)
The Seventh Seal
And when he had opened the seventh seal, there was silence in heaven about the space of half an hour.
The Lamb is Jesus - He gave himself as a sacrifice for our sins. He was innocent, just like a little lamb that is sacrificed to God in the Judaic tradition.
Jesus and the Antichrist are not the only ones who will wage war during the Tribulation. God will step back and people will kill one another unlike anything we've ever seen. Even the carnage of the Holocaust will pale by comparison. This horse is red to represent blood that will be shed.
During the Tribulation the inequality between the rich and poor will be even more dramatic. Basic sustinence items like bread ("wheat" and "barley") will be in short supply and only the rich will be able to afford to buy them. On the other hand, luxury items ("oil" and "wine") will be more abundant, so the rich will be able to obtain those items as well. Food products that sustain life will be the hardest to get. Without the charity of Christian organizations and individuals (since they are now gone) famine will run rampant and many will die of starvation and malnutrition.
The first horse is white, which would lead one to suspect that the rider is Jesus, but it is probably more accurately the Antichrist. He will first emerge as a man of peace, he will eventually rule over the entire world and destroy all those who do not worship him. (Christ will appear at the end of the Tribulation period and defeat both the Antichrist and Satan.)
1 - ANTICHRIST
The fourth rider is commonly called "Pestilence", probably because of the sickly pale green color mentioned, but the Bible literally calls this horseman Death. Those who were not killed by Antichrist, during war and battles between humans or famine may perish during this judgement, which includes war (sword), famine (hunger) and a terrifying alternative: "with the beasts of the earth."
Throughout history up to the present day, Christians have been persecuted and murdered for their testimony. Eventually, Christ will avenge their deaths. Before that though, many who will come to the correct conclusion that Jesus is the Christ DURING the Tribulation period will reject the Antichrist and refuse to worship him or his image or take his mark. These "Tribulation Saints" will be killed for their testimony during the reign of the Antichrist. This must be fulfilled before God avenges the deaths of all Christians who have been persecuted throughout history.
As strange as the weather and nature has been these past years in history, none of the earthquakes, meteor showers or other natural phenomenon can compare to what is in store when the "great day of his wrath is come". EVERY island and mountain on earth will be moved! Brave men of power will cower in fear and realization that these awful disasters are from God. They will be ashamed and not want to face God. Anyone who had previously attributed the disappearance of Christians from the earth to aliens will now know that there is a God and He has come in wrath! They will not realize, however, that death won't spare them from His judgment.