1 Thessalonians 5:2, 4-6

For yourselves know perfectly that the day of the Lord so cometh as a thief in the night.

But ye, brethren, are not in darkness, that that day should overtake you as a thief: for ye are all sons of light, and sons of the day: we are not of the night, nor of darkness; so then let us not sleep, as do the rest, but let us watch and be sober.