Paul, Silvanus, and Timothy, to the assembly of the Thessalonians in God the Father and the Lord Jesus Christ: Grace to you and peace from God our Father and the Lord Jesus Christ.
At the time he wrote this epistle, Silas and Timothy were with Paul. "Silvanus" was the Roman form of his name, which Paul preferred over "Silas." Luke used "Silas" (Acts 15:22; et al.). No one knows if this Silvanus is the same man whom Peter mentioned in 1 Peter 5:12. Silas and Timothy were Paul’s primary associates on his second missionary journey during which the church at Thessalonica came into existence (Acts 15:40). We know more about Timothy’s background than we do about Silas’. Paul may have led Timothy to faith in Christ on the first missionary journey (1 Timothy 1:2; Acts 13-14). Timothy had recently returned to Paul in Corinth when Paul wrote this letter. He had come from Thessalonica bearing news of conditions in the church there (1 Thessalonians 3:1-2; 1 Thessalonians 3:6). The Thessalonians knew all three men personally.