Romans 13:11-13 calls believers to wake from slumber and put on light, directly reinforcing the 'not in darkness' and watchfulness of 1 Thessalonians 5:4.

Colossians 1:13 states believers have been rescued from darkness into Christ's kingdom—the same deliverance from darkness implied in 1 Thessalonians 5:4.

1 Peter 2:9 describes being called out of darkness into wonderful light—echoing the 'not in darkness' status of believers in 1 Thessalonians 5:4.

1 John 2:8 says the darkness is passing and the true light shines—aligning with the idea that believers are not in darkness and the day is near.

In Luke 1:79, light comes to those in darkness — here Paul says believers are no longer in darkness, so the day won't surprise them.

In John 1:9, Jesus is the true light — believers are children of light because of him, no longer in darkness.

In Acts 26:18, Paul's mission is to turn people from darkness to light — believers have been turned, so they are not in darkness.

In 2 Corinthians 6:14, Paul asks what fellowship light has with darkness — echoing the same contrast between believers and darkness found here.

In Ephesians 5:8, Paul says believers were darkness but are now light — directly paralleling the identity change from darkness to light here.

In Revelation 3:3, Jesus warns he will come like a thief — the same metaphor used here for the day of the Lord that does not overtake believers in darkness.

In 2 Timothy 4:8, Paul speaks of the crown awarded on 'that day' — the same day of Christ's coming that believers are not surprised by.

In Deuteronomy 28:45, curses overtake the disobedient — here Paul says believers are not in darkness, so the Day of the Lord will not overtake them.