According to the text, what does Paul remind in 1 Thessalonians 5?

In 1 Thessalonians 5, Paul emphasizes the importance of vigilance and readiness among believers. He desires for the church to be alert and sober, underscoring that the return of the Lord can happen unexpectedly, like a thief in the night. This call to vigilance is a major theme in the chapter, encouraging followers of Christ to live in a way that reflects their faith and hope in God's promises. Paul assures believers not to be caught off guard by the day of the Lord, reinforcing the need for spiritual watchfulness and moral integrity.

The other options present ideas not supported by the text. For instance, while Paul discusses the 'day of the Lord,' he does not indicate that it has already occurred, nor does he talk about a lack of resurrection or the start of the millennium in this particular context. Thus, the emphasis on being vigilant aligns closely with the overall message of preparedness that Paul is conveying to the Thessalonian church.