We sent Timothy, our brother and co-worker for God in proclaiming the gospel of Christ, to strengthen and encourage you for the sake of your faith, so that no one would be shaken by these persecutions. Indeed, you yourselves know that this is what we are destined for. In fact, when we were with you, we told you beforehand that we were to suffer persecution; so it turned out, as you know. For this reason, when I could bear it no longer, I sent to find out about your faith; I was afraid that somehow the tempter had tempted you and that our labor had been in vain. (1 Thessalonians 3:2-5, NRSV)
And sent Timotheus, our brother, and minister of God, and our fellow labourer in the gospel of Christ, to establish you, and to comfort you concerning your faith: That no man should be moved by these afflictions: for yourselves know that we are appointed thereunto. For verily, when we were with you, we told you before that we should suffer tribulation; even as it came to pass, and ye know. For this cause, when I could no longer forbear, I sent to know your faith, lest by some means the tempter have tempted you, and our labour be in vain. (1 Thessalonians 3:2-5, KJV)
So the Thessalonians knew they were going to get bullied a little for their beliefs. After all, Paul warned them. (Trust us, he knew a thing or two about getting bullied for his beliefs.) But Paul's still worried that they might have fallen by the wayside. Luckily, perseverance is the Thessalonians' strong suit.