Matthew 24:21-22

for then shall be a time of great tribulation, such as has not been from the beginning of the world until now, no, and never shall be again.

Mark 13:19

For those will be days of suffering the like of which has never been from the beginning of God's creation until now, and never shall be.

Acts 2:20

Into darkness shall the sun be turned, And into blood the moon, Ere the day of the Lord come, that great and terrible day.

Romans 11:26

And so all Israel will be saved, as it is written. The deliver will come from Zion, He will banish all ungodliness from Jacob;

Revelation 6:17

For the Great Day of their wrath 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
Into darkness shall the sun be turned, And into blood the moon, Ere the day of the Lord come, that great and terrible day.
Revelation 6:17
For the Great Day of their wrath has come, And who is able to stand?"

So

Matthew 24:21
for then shall be a time of great tribulation, such as has not been from the beginning of the world until now, no, and never shall be again.
Mark 13:19
For those will be days of suffering the like of which has never been from the beginning of God's creation until now, and never shall be.

But

Romans 11:26
And so all Israel will be saved, as it is written. The deliver will come from Zion, He will banish all ungodliness from Jacob;