Paul, Silvanus, and Timothy, to the assembly of the Thessalonians in God our Father, and the Lord Jesus Christ:
In many of his letters, Paul mentions the city to which he is writing as he does here, for example: "the church which is at Cenchreae" (Romans 16:1); "the church of the Laodiceans" (Colossians 4:16); "the church of the Thessalonians" (1 Thessalonians 1:1). On other occasions, instead of naming individual cities, Paul names the regions, such as "the churches of Galatia" (1 Corinthians 16:1; Galatians 1:2); "the churches of Asia" (1 Corinthians 16:19); "the churches of Macedonia" (2 Corinthians 8:1); "the churches of Judea" (Galatians 1:22). The phrase (churches of ...) should be understood as different assemblies, congregations, or bodies of Christ, and not different denominations, sectarians, or other religious groups.