1 Thessalonians 5:4 (ESV)

4 But you are not in darkness, brothers, for that day to surprise you like a thief.

Although Paul again uses the word brothers, he again addresses the whole congregation. Everyone must be addressed. Fortunately, as the apostle knows, they do not live as people of the world. The light of Christ has risen for them. They walk in his light (see also John 1:4–5 and John 8:12). This makes the apostle glad, and he is thankful for this. The day of Jesus’ coming will not surprise them like a thief.