1 Thessalonians 5:2, 4-6

For you know quite well that the day of the Lord’s return will come unexpectedly, like a thief in the night.

But you aren’t in the dark about these things, dear brothers and sisters, and you won’t be surprised when the day of the Lord comes like a thief. For you are all children of the light and of the day; we don’t belong to darkness and night. So be on your guard, not asleep like the others. Stay alert and be clearheaded.