It was through the teaching of Paul, Silas, and Timothy when they were on their founding visit to the city that the Thessalonian believers had learned about the reality of suffering in the Christian life. According to Acts 17:3, Paul had taught in the synagogue of Thessalonica about the suffering and death of the Lord Jesus Christ. Of course, Christ’s death is significant for its saving power, but it is also a pattern for his followers, as Paul reminded Timothy some years later: all who desire to live a godly life in Christ Jesus will be persecuted
(2 Timothy 3:12; see also Philippians 3:10). This was part of the basic teaching given to the Thessalonians, as the rest of this sentence indicates.1
4 For when we were with you, we kept telling you beforehand that we were to suffer affliction, just as it has come to pass, and just as you know.