It is because in this life/time/age we have been baptized by the Holy Spirit when we believed that when Christ comes again, we shall be caught up with the Lord in the air, and all who remain on the earth shall be consumed by the fire of God's wrath. And life/time/age given this earth shall be no longer.
Except the baptism of fire does not destroy human flesh. It destroys the human works on the earth. You have the flesh consumed as an improper interpretation. Those symbolized as goats are physically cast alive into the LOF. It never states their flesh is consumed. The point of the Second Coming is not the end.
There is still the final harvest that Jesus and the angels are physically on earth and part of. The explanation Jesus gave is clear and not a parable. You can interpret the parable how ever you like, but when Jesus explained the parable, why would you state something different than Jesus explained?
"Then Jesus sent the multitude away, and went into the house: and his disciples came unto him, saying, Declare unto us the parable of the tares of the field. He answered and said unto them, He that soweth the good seed is the Son of man; The field is the world; the good seed are the children of the kingdom; but the tares are the children of the wicked one; The enemy that sowed them is the devil; the harvest is the end of the world; and the reapers are the angels. As therefore the tares are gathered and burned in the fire; so shall it be in the end of this world. The Son of man shall send forth his angels, and they shall gather out of his kingdom all things that offend, and them which do iniquity;"
Why do so many deny that Jesus and the angels are on the earth during the Trumpets and Thunders, the time of Jacob's trouble, and the final harvest? And the end of the world in verse 49 is not the end of the earth nor time, but the end of an age. Amil deny the next age that is to come called the Millennium Kingdom. An age is a unit of time. But time does not end nor creation. So earth is not removed as written in Revelation 20:11
"And I saw a great white throne, and him that sat on it, from whose face the earth and the heaven fled away; and there was found no place for them."
This end is not the alleged end as in Matthew 13. Matthew 13 is the end of Adam's dead corruptible flesh. 8 billion people are not just instantly consumed by fire physically and then their souls sent to heaven or sheol. That is not even what 2 Peter 3 tells us. When Jesus is baptizing the earth in fire it is destroying the works that make the flesh comfortable. That is why it is GT. People will literally have nothing. Those post trib people think the church is to endure this time on earth with nothing, even while Jesus and the angels are bringing in the final harvest of billions of souls. At the 6th Seal Jesus immediately starts to restore the earth in and around Jerusalem. At the same time, even Satan and those world leaders are attempting to restore normality, and that is the healing of the wounded head of the dragon. The earth will Marvel, because Satan will be offering a temporary restoration at the same time as Jesus and the angels are at work. That is not fictional interpretation of wild imagination. That is what Matthew 13 and Revelation 13 declare.
"And I saw one of his heads as it were wounded to death; and his deadly wound was healed: and all the world wondered after the beast."
That is a political restoration, and we have been led to believe that government involvement in times of GT can restore things back to normal.
"but the tares are the children of the wicked one; The enemy that sowed them is the devil; the harvest is the end of the world."
So Satan is also at work gathering those who follow him and his miraculous government in response to this baptism of fire according to 2 Peter 3.
"But the day of the Lord will come as a thief in the night; in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up. Seeing then that all these things shall be dissolved,"
"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; 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. And the heaven departed as a scroll when it is rolled together; and every mountain and island were moved out of their places. 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; And said to the mountains and rocks, Fall on us, and hide us."
Of course Satan and human government is going to step in and all those rich people in control are going to want that control enforced, and will follow Satan's will to see that they have an answer in response to billions who just had everything taken away by God at the Second Coming, the 6th Seal. That is the baptism of fire.