Brothers: Greek adelphoi, a term for family members, both male and female.
thank God: The apostle Paul starts by expressing thanks for the Thessalonians’ faith and love, and how they are enduring (1:4). These are key Christian virtues (see 1 Corinthians 13:13; Colossians 1:4–5; Hebrews 10:21–24; 1 Peter 2:1–22). These virtues were increasing in the church despite the bad treatment they encountered (2 Thessalonians 1:5).