13And we also thank God constantly for this, that when you received the word of God, which you heard from us, you accepted it not as the word of men but as what it really is, the word of God, which is at work in you believers. 14For you, brothers, became imitators of the churches of God in Christ Jesus that are in Judea. For you suffered the same things from your own countrymen as they did from the Jews, 15 who killed both the Lord Jesus and the prophets, and drove us out, and displease God and oppose all mankind 16 by hindering us from speaking to the Gentiles that they might be saved—so as always to fill up the measure of their sins. But God’s wrath has come upon them at last!Hmmm....can you imagine the gratitude Paul would have felt to the Thessalonians for how they reacted to the word of God preached to them? They listened, they understood, they turned to God. They didn't react by wanting to beat him, imprison him or any other harsh negative reaction. Their's was a reaction of acceptance. They KNEW that Paul spoke God's words.
And therefore they became imitators of other Christian believers. They suffered for their faith just as the Jewish believers did...but at the hands of their very own countrymen.
So Paul gives thanks to them. Not just once, but constantly. And he doesn't just thank them, he thanks God for them. To me it's like he's saying..."wow God, these people, these imitators of you, that have have allowed me to witness to ...they love you God! Thank you so much for letting me a be a part of this. See how they witness of who you are God? thanks!" And doing that over and over and over again.
My praise of God should be the same...particularly for how people witness of who God is. :)