WHEN will the Great Tribulation occur?

Q. When will be the Great Tribulation?  Will it be BEFORE or AFTER Jesus returns?

A. Trying to figure out what is going on in the Book of Revelation can be frustrating. We can gain a better understanding of Revelation by looking at Jesus' Olivet prophecy recorded in Matthew 24, Mark 13 and Luke 21. This prophecy is rather long, so for reference I've included some of the most important scriptures relative to your question from the Matthew 24 account of Jesus' words. For study purposes I suggest reading the full accounts in all three books.

"And Jesus went out, and departed from the temple: and his disciples came to him for to show him the buildings of the temple. And Jesus said unto them, See ye not all these things? verily I say unto you, There shall not be left here one stone upon another, that shall not be thrown down. And as he sat upon the mount of Olives, the disciples came unto him privately, saying, Tell us, when shall these things be? and what shall be the sign of thy coming, and of the end of the world?

"And Jesus answered and said unto them, Take heed that no man deceive you. For many shall come in my name, saying, I am Christ; and shall deceive many. And ye shall hear of wars and rumours of wars: see that ye be not troubled: for all these things must come to pass, but the end is not yet. For nation shall rise against nation, and kingdom against kingdom: and there shall be famines, and pestilences, and earthquakes, in divers places. All these are the beginning of sorrows. Then shall they deliver you up to be afflicted, and shall kill you: and ye shall be hated of all nations for my name’s sake. . . .

"When ye therefore shall see the abomination of desolation, spoken of by Daniel the prophet, stand in the holy place, (whoso readeth, let him understand:) Then let them which be in Judaea flee into the mountains: . . . . For then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be. And except those days should be shortened, there should no flesh be saved: but for the elect’s sake those days shall be shortened.

"Wherefore if they shall say unto you, Behold, he is in the desert; go not forth: behold, he is in the secret chambers; believe it not. For as the lightning cometh out of the east, and shineth even unto the west; so shall also the coming of the Son of man be. . . .

"Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken: And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory.

"And he shall send his angels with a great sound of a trumpet, and they shall gather together his elect from the four winds, from one end of heaven to the other. " (Matthew 24:1-9, 15-16, 21-22, 26-27, 29-31)

In the Olivet prophecy Jesus provides us with a basic outline of the events leading up to His second coming. In Matthew's account Jesus speaks of a Great Tribulation which will be like nothing the world has ever seen (Matthew 24:21-22 ). It will be so bad that if God does not intervene, humanity will be destroyed. After speaking of the Great Tribulation, Jesus warns his disciples about false Christs and false prophets who will seek to mislead them into believing Jesus has already secretly come (Matthew 24:23-26). But Jesus says that when He returns everyone will see Him. He uses the illustration of lightning, which is hard to hide, as everyone can see it (Matthew 24:27-28). Jesus continues, saying that after the Tribulation the sun will darken, the moon will not be as bright and stars will fall from the sky. Then, after all this He will return, with everyone seeing Him. A trumpet blast will also accompany His return (Matthew 24:29-31).