Hi Edward
I'm sorry. This is the question that you asked of me:
Please forgive me if I misunderstood exactly what it was that you were asking about the tribulation. The tribulation is just the natural working out of man's wicked and evil heart upon the earth. God's word tells us, most clearly in the letter to the Romans all of the wickedness that is going to come upon men because they have refused the mercy and grace of God, their Creator. God is allowing it because we are living in the days of God's patience, as Peter writes to us.
God spent some 1500 years cobbling together His Scriptures among His people, Israel. Then He sent His Son as our sacrifice for sin. Now, that part of God's work in providing our salvation is finished. That's exactly what Jesus said as he drew his last breath here on the earth with us. "It is finished!" He proclaimed. What was finished? The 'mechanics' if you will, of God's great plan of salvation. The truth had been written that tells us all about the things the Jesus was going to be doing so that we would know him when he came...but we didn't. But God sent Jesus, in the due course of time. He died. Now, we live in the days of God's patience when the gospel will be preached to all mankind and some will come to the knowledge of His salvation.
But the natural working out of mankind that is living like this...
For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that people are without excuse. For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened. Although they claimed to be wise, they became fools and exchanged the glory of the immortal God for images made to look like a mortal human being and birds and animals and reptiles. Therefore God gave them over in the sinful desires of their hearts to sexual impurity for the degrading of their bodies with one another. They exchanged the truth about God for a lie, and worshiped and served created things rather than the Creator—who is forever praised. Amen.
Because of this, God gave them over to shameful lusts. Even their women exchanged natural sexual relations for unnatural ones. In the same way the men also abandoned natural relations with women and were inflamed with lust for one another. Men committed shameful acts with other men, and received in themselves the due penalty for their error. Furthermore, just as they did not think it worthwhile to retain the knowledge of God, so God gave them over to a depraved mind, so that they do what ought not to be done. They have become filled with every kind of wickedness, evil, greed and depravity. They are full of envy, murder, strife, deceit and malice. They are gossips, slanderers, God-haters, insolent, arrogant and boastful; they invent ways of doing evil; they disobey their parents; they have no understanding, no fidelity, no love, no mercy. Although they know God’s righteous decree that those who do such things deserve death, they not only continue to do these very things but also approve of those who practice them.
I would ask that you read that carefully and sit back and ruminate on how bad people are going to be treating one another if they are living with a depraved mind, so that they do what ought not to be done. An entire globe of billions upon billions of people, and they are all filled with every kind of wickedness, evil, greed and depravity. They are full of envy, murder, strife, deceit and malice. They are gossips, slanderers, God-haters, insolent, arrogant and boastful; they invent ways of doing evil;
Then you throw Jesus' words in there, that he has warned us that a time is coming that will be worse than things have ever been before upon the earth. There is going to be a great tribulation that is going to be a time of great persecution upon the believers and those faithful to God. That time of great tribulation will come because the earth will be filled with people living as my last paragraph describes and they are going to be going after and attacking the people of God.
But then God has promised that He is going to cut short those days. He's going to do that by sending Jesus, as explained in the Revelation chapter 14:14+. God is going to cut short the days of great tribulation and usher in his judgment and wrath upon the vile and wicked unbelieving. Those will then become the days of God's wrath. And what will be happening is explained to us in the Revelation of Jesus as the bowl judgments.
But the reason there is a Great Tribulation is just because the entire globe will be filled with wicked, evil people who don't love anyone but themselves, who slander anyone they desire, to hate and murder and envy and strife and deceit and malice. Those people will get tired of hearing us calling them to repent and be saved. They are going to be people who believe that the earth was created through some natural processes as our current popular science teaches. They're not going to believe that there is a God or that He had anything to do with why we are here and that the only reason each one of us even breathes is God. So, they are going to come after the people of God. They're going to hate us even more than they hate their other equally wicked friends, neighbors and just other living people.
Sorry if I misunderstood 'what' exactly you were asking, but now that you've clarified it...this is it. The Great Tribulation comes upon the earth because the wickedness of man will reach an apex. The Antichrist will be revealed, and as we've been warned about him, he's going to put himself in the place of God for all of those wicked, evil people that don't know God. That's all going to boil over into a tempest of hate and anger and persecution that Jesus tells us will be worse that it has ever been or ever will be again. But, because God has determined to cut short those days, He is going to send His Son to collect those who are his, which the angel speaking to John tells him are those who came out of the Great Tribulation, and the God's wrath, as accounted for in the last chapters of the Revelation of Jesus.
The believers will have been taken out of the Great Tribulation:
Then one of the elders asked me, “These in white robes—who are they, and where did they come from?” I answered, “Sir, you know.” And he said, “These are they who have come out of the great tribulation; they have washed their robes and made them white in the blood of the Lamb.
Did you get that? This creature is telling John that the group of people who sees in his vision are 'those who have come out of...what?...THE GREAT TRIBULATION. The exact same words to describe the exact same time that Jesus spoke of as the days of Great Tribulation. That is not the same as the days in which God's wrath will be loosed upon mankind...after the believers have been harvested out of the earth.
God bless,
Ted
