Note 11 at 1 Th. 1:7: The Thessalonians were faithful to follow the Lord and His apostles even though receiving the message of Christ meant serious trouble for them. In so doing they became examples to all other believers and were worthy of being imitated. That's what the word "ensamples" means. The dictionary defines "ensample" as "one who is worthy of imitation or duplication."

Paul had commended them for following his example and now he is saying that they have done so well that others should imitate them.