1 Thessalonians 5:2-6

For you yourselves know perfectly well that the day of the [return of the] Lord is coming just as a thief [comes unexpectedly and suddenly] in the night. While they are saying, “Peace and safety [all is well and secure!]” then [in a moment unforeseen] destruction will come upon them suddenly like labor pains on a woman with child, and they will absolutely not escape [for there will be no way to escape the judgment of the Lord]. But you, believers, [all you who believe in Christ as Savior and acknowledge Him as God’s Son] are not in spiritual darkness [nor held by its power], that the day [of judgment] would overtake you [by surprise] like a thief; for you are all sons of light and sons of day. We do not belong to the night nor to darkness. So then let us not sleep [in spiritual indifference] as the rest [of the world does], but let us keep wide awake [alert and cautious] and let us be sober [self-controlled, calm, and wise].