Matthew 24:21-22

for it will be a time of great suffering, such as never has been from the beginning of the world till now, and assuredly never will be again.

Mark 13:19

For those will be times of suffering the like of which has never been from the first creation of God's world until now, and assuredly never will be again;

Acts 2:20

The sun shall be turned into darkness and the moon into blood, to usher in the day of the Lord-- that great and illustrious day;

Romans 11:26

and so all Israel will be saved. As is declared in Scripture, "From Mount Zion a Deliverer will come: He will remove all ungodliness from Jacob;

Revelation 6:17

for the day of His anger--that great day--has come, and who is able to stand?"

Treasury of Scripture Knowledge

Summary

Alas! for that day is great, so that none is like it: it is even the time of Jacob's trouble; but he shall be saved out of it.

Bible References

For

Acts 2:20
The sun shall be turned into darkness and the moon into blood, to usher in the day of the Lord-- that great and illustrious day;
Revelation 6:17
for the day of His anger--that great day--has come, and who is able to stand?"

So

Matthew 24:21
for it will be a time of great suffering, such as never has been from the beginning of the world till now, and assuredly never will be again.
Mark 13:19
For those will be times of suffering the like of which has never been from the first creation of God's world until now, and assuredly never will be again;

But

Romans 11:26
and so all Israel will be saved. As is declared in Scripture, "From Mount Zion a Deliverer will come: He will remove all ungodliness from Jacob;