(Matthew 24:1 -31) Jesus left the temple and was going away, when his disciples came to point out to him the buildings of the temple. But he answered them, “You see all these, do you not? Truly, I say to you, there will not be left here one stone upon another, that will not be thrown down.”
As he sat on the Mount of Olives, the disciples came to him privately, saying, “Tell us, when will this be, and what will be the sign of your coming and of the close of the age?” And Jesus answered them, “Take heed that no one leads you astray. For many will come in my name, saying, ‘I am the Christ,’ and they will lead many astray. And you will hear of wars and rumors of wars; see that you are not alarmed; for this must take place, but the end is not yet. For nation will rise against nation, and kingdom against kingdom, and there will be famines and earthquakes in various places: all this is but the beginning of the birth-pangs.
“Then they will deliver you up to tribulation, and put you to death; and you will be hated by all nations for my name’s sake. And then many will fall away, and betray one another, and hate one another. And many false prophets will arise and lead many astray. And because wickedness is multiplied, most men’s love will grow cold. But he who endures to the end will be saved. And this gospel of the kingdom will be preached throughout the whole world, as a testimony to all nations; and then the end will come.
“So when you see the desolating sacrilege spoken of by the prophet Daniel, standing in the holy place, then let those who are in Judea flee to the mountains; let him who is on the housetop not go down to take what is in his house; and let him who is in the field not turn back to take his mantle. And alas for those who are with child and for those who give suck in those days! Pray that your flight may not be in winter or on a sabbath. For then there will be great tribulation, such as has not been from the beginning of the world until now, no, and never will be. And if those days had not been shortened, no human being would be saved; but for the sake of the elect those days will be shortened. Then if any one says to you, ‘Lo, here is the Christ!’ or ‘There he is!’ do not believe it. For false Christs and false prophets will arise and show great signs and wonders, so as to lead astray, if possible, even the elect. Lo, I have told you beforehand. So, if they say to you, ‘Lo, he is in the wilderness,’ do not go out; if they say, ‘Lo, he is in the inner rooms,’ do not believe it. For as the lightning comes from the east and shines as far as the west, so will be the coming of the Son of man. Wherever the body is, there the eagles will be gathered together.
“Immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light, and the stars will fall from heaven, and the powers of the heavens will be shaken; then will appear the sign of the Son of man in heaven, and then all the tribes of the earth will mourn, and they will see the Son of man coming on the clouds of heaven with power and great glory; and he will send out his angels with a loud trumpet call, and they will gather his elect from the four winds, from one end of heaven to the other.”
(Revelation 6: 9 - 11) When he opened the fifth seal, I saw under the altar the souls of those who had been slain for the word of God and for the witness they had borne; they cried out with a loud voice, “O Sovereign Lord, holy and true, how long before thou wilt judge and avenge our blood on those who dwell upon the earth?” Then they were each given a white robe and told to rest a little longer, until the number of their fellow servants and their brethren should be complete, who were to be killed as they themselves had been.
After this I looked, and behold, a great multitude which no man could number, from every nation, from all tribes and peoples and tongues, standing before the throne and before the Lamb, clothed in white robes, with palm branches in their hands, and crying out with a loud voice, “Salvation belongs to our God who sits upon the throne, and to the Lamb!” And all the angels stood round the throne and round the elders and the four living creatures, and they fell on their faces before the throne and worshiped God, saying, “Amen! Blessing and glory and wisdom and thanksgiving and honor and power and might be to our God for ever and ever! Amen.” Then one of the elders addressed me, saying, “Who are these, clothed in white robes, and whence have they come?” I said to him, “Sir, you know.” And he said to me, “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.”
"For in those days there will be such tribulation as has not been from the beginning of the creation which God created until now, and never will be."