Paul's gospel mission was dangerous.  Before arriving in Thessalonica, he and Silas had commanded an evil spirit to leave a disturbed slave girl, in Philippi.  Her owners made money out of her occult predictions, and they were very angry that their source of income had gone.  They dragged Paul and Silas to the marketplace accusing them of practising an illegal religion.  That excited a mob to attack the Christians and, to restore public order, the magistrates ordered that they be stripped and severely flogged in public before being shackled (Acts 16:16-40).
 
But the Lord was at work in it all.  Instead of crying in agony in their prison cell, Paul and Silas prayed and sang hymns of praise to God.  At midnight there was an earthquake and the prison doors flew open.  All the prisoners' chains were released.  As the jailer was about to commit suicide (fearing that all his charges would escape and leave him culpable), Paul took command.  Nobody tried to leave and the jailer, with his family, trusted Jesus that night.  The next day, the magistrates set them free and, after encouraging some new believers in the city, left in pain for Thessalonica.  It only took a few weeks for another anti-Jesus crowd to riot in that city also (Acts 17:5-9).  But by then another church had been formed (Acts 17:2-4).
 
Paul wanted to reassure them that the angry reaction to the gospel was not unusual.  It did not mean that the gospel was bad news.  Indeed, both in Philippi and Thessalonica people had believed in Jesus.  Telling the gospel is never easy and is only possible through the power and strength of God.  But Paul’s conviction was that as God had called him to that work, God would enable him to do it … despite persecution. 
 
Gospel proclamation goes hand-in-hand with hostility from the world ... but God also gives great peace of heart.  Jesus said, "I have told you these things, so that in me you may have peace. In this world you will have trouble. But take heart! I have overcome the world." (John 16:33).  It would be nice to think that faith in Jesus brings undiluted happiness.  But unless people love Him, they will not want to obey Him, and they may persecute His representatives.  But that is no reason to be quiet about Jesus; it shows that the gospel message is even more necessary.  As the Lord's people dare to speak about Jesus, He gives courage and joy to His people to deal with the suffering and see others put their trust in Him.