Paul's use of 'You know'; calling the Thessalonians as witnesses in the defense of his ministry; when truth is accurately presented; lives are changed=greatest witness to the truth of Scripture; 8 elements of effective ministry; 1Jo 3; 1Jo 4; the offer of salvation is free for the taking:remember the Thief on the Cross--anything he could not do on the cross cannot be a requirement for salvation. You cannot mingle the work of man with God's GIFT of salvation; 2Co 4; Jam 2:12; Mat 5:10; Joh 3:16; Rom 5:8; God sends out His Word for our benefit; When the Word starts to work; the believer begins to be changed; The highest compliment the devil's world can pay the believer is to hate and persecute him-- because of the message he believes: God's Word changes lives and world doesn't like it! ; persecution follows faith; Satan uses people who are willing to be used; Paul will share a crown with the Thessalonians that the Corinthians and the Galatians cannot share.
The Thessalonians were persecuted for their faith. Paul's first letter to them provides comfort, reminding them of the details of Christ's return for His Church ("The Blessed Hope") and providing practical spiritual lessons for living.