Luke 12:40

So, you also should be ready, for the Son of man will return at a time when you least expect Him."

Matthew 24:42

Therefore be alert, for you do not know on what day the Lord will come.

Matthew 24:44

Therefore, you also should be ready, for the Son of man will come at a time when you least expect Him.

Matthew 25:13

Therefore, you should be watchful, for you do not know the day or hour [i.e., when the Son of man will return].

Mark 13:33-36

"You should pay attention; be alert and pray, for you do not know when the time will come [i.e., for the Lord to return].

Luke 21:34-36

"But pay attention to yourselves so that your hearts do not become overburdened by carousing, and drunkenness, and the worries of life. [If you do], that 'day' [i.e., Jesus' second coming and judgment] will arrive suddenly, like a trap [i.e., which catches an animal by surprise].

Romans 13:11

Now this [is another reason for observing the law of love]: You should know that it is about time to wake up out of your [spiritual] sleep, because [the day of our final] salvation is now nearer to us than when we first believed [in Christ].

Romans 13:14

But clothe yourselves with the Lord Jesus Christ and do not make any plans for satisfying the strong desires of your flesh [i.e., your appetites for sinful pleasures].

1 Thessalonians 5:6

So then, we should not be [spiritually] asleep, like the rest [i.e., the unsaved world], but we should be alert and sober [i.e., in control of our senses].

2 Peter 3:12-14

[while] looking forward to, and earnestly desiring the day of God to come, when the heavens will be set ablaze and dissolved by fire and the elements [See verse 10] will melt with intense heat.

Revelation 19:7

We should rejoice and be extremely glad, and we should give honor to Him. For the time has come for the Lamb's marriage, and His bride has prepared herself [for the wedding].

Treasury of Scripture Knowledge

Summary

Be ye therefore ready also: for the Son of man cometh at an hour when ye think not.

Bible References

General references

Luke 21:34
"But pay attention to yourselves so that your hearts do not become overburdened by carousing, and drunkenness, and the worries of life. [If you do], that 'day' [i.e., Jesus' second coming and judgment] will arrive suddenly, like a trap [i.e., which catches an animal by surprise].
Matthew 24:42
Therefore be alert, for you do not know on what day the Lord will come.
Matthew 25:13
Therefore, you should be watchful, for you do not know the day or hour [i.e., when the Son of man will return].
Mark 13:33
"You should pay attention; be alert and pray, for you do not know when the time will come [i.e., for the Lord to return].
Romans 13:11
Now this [is another reason for observing the law of love]: You should know that it is about time to wake up out of your [spiritual] sleep, because [the day of our final] salvation is now nearer to us than when we first believed [in Christ].
1 Thessalonians 5:6
So then, we should not be [spiritually] asleep, like the rest [i.e., the unsaved world], but we should be alert and sober [i.e., in control of our senses].
2 Peter 3:12
[while] looking forward to, and earnestly desiring the day of God to come, when the heavens will be set ablaze and dissolved by fire and the elements [See verse 10] will melt with intense heat.
Revelation 19:7
We should rejoice and be extremely glad, and we should give honor to Him. For the time has come for the Lamb's marriage, and His bride has prepared herself [for the wedding].