The "day of the Lord" will take people by surprise

1 Thessalonians 5:1-9

1 Now, brothers, about times and dates we do not need to write to you,

2 for you know very well that the day of the Lord will come like a thief in the night.

3 While people are saying, "Peace and safety," destruction will come on them suddenly, as labor pains on a pregnant woman, and they will not escape.

4 But you, brothers, are not in darkness so that this day should surprise you like a thief.

5 You are all sons of the light and sons of the day. We do not belong to the night or to the darkness.

6 So then, let us not be like others, who are asleep, but let us be alert and self-controlled.

7 For those who sleep, sleep at night, and those who get drunk, get drunk at night.

8 But since we belong to the day, let us be self-controlled, putting on faith and love as a breastplate, and the hope of salvation as a helmet.

9 For God did not appoint us to suffer wrath but to receive salvation through our Lord Jesus Christ.

(New International Version translation)