The purposes for the tribulation are to bring Israel to a saving knowledge of Christ and to pour out judgment on unbelieving people and nations.
Then it will be, if they do not believe you, nor heed the message of the first sign, that they may believe the message of the latter sign. (Exodus 4:8 NKJV)
When thou art in tribulation, and all these things are come upon thee, even in the latter days, if thou turn to the LORD thy God, and shalt be obedient unto his voice; (For the LORD thy God is a merciful God;) he will not forsake thee, neither destroy thee, nor forget the covenant of thy fathers which he sware unto them.
And pray that your flight may not be in winter or on the Sabbath. For then there will be great tribulation, such as has not been since the beginning of the world until this time, no, nor ever shall be. And unless those days were shortened, no flesh would be saved; but for the elect’s sake those days will be shortened.
“So when you see the ‘abomination of desolation,’ spoken of by Daniel the prophet, standing where it ought not” (let the reader understand), “then let those who are in Judea flee to the mountains. Let him who is on the housetop not go down into the house, nor enter to take anything out of his house.
Jeremiah 30:6-8 Jacob's Trouble
Ask now, and see,
Whether a man is ever in labor with child?
So why do I see every man with his hands on his loins
Like a woman in labor,
And all faces turned pale?
Alas! For that day is great,
So that none is like it;
And it is the time of Jacob’s trouble,
But he shall be saved out of it.
‘ For it shall come to pass in that day,’
Says the LORD of hosts,
‘ That I will break his yoke from your neck,
And will burst your bonds;
Foreigners shall no more enslave them.
Isaiah 28:18--Israel's Covenant of Death
Your covenant with death will be annulled,
And your agreement with Sheol will not stand;
When the overflowing scourge passes through,
Then you will be trampled down by it.
Revelation 6:16 Wrath of the Lamb
“Fall on us and hide us from the face of Him who sits on the throne and from the wrath of the Lamb!
Revelation 3:10 The hour of trial or temptation
Because you have kept My command to persevere, I also will keep you from the hour of trial which shall come upon the whole world, to test those who dwell on the earth.
Fire from Heaven
He performs great signs, so that he even makes fire come down from heaven on the earth in the sight of men.
2 Kings 1:9-10
Then the king sent to him a captain of fifty with his fifty men. So he went up to him; and there he was, sitting on the top of a hill. And he spoke to him: “Man of God, the king has said, ‘Come down!’”
So Elijah answered and said to the captain of fifty, “If I am a man of God, then let fire come down from heaven and consume you and your fifty men.” And fire came down from heaven and consumed him and his fifty.