2 Thes. 2:1-2 (ESV)
Now concerning the coming of our Lord Jesus Christ and our being gathered together to him, we ask you, brothers,  not to be quickly shaken in mind or alarmed, either by a spirit or a spoken word, or a letter seeming to be from us, to the effect that the day of the Lord has come.
It’s funny that the letters to the Thessalonians are of such importance to all the Millenialists, and yet they tend to ignore it. They use it to scare rather than to comfort. Paul wrote to comfort, that ought to be our goal as pastors and Christians. It seems that the Thessalonians were scared that they had missed the day of the Lord. Evidently they thought the lord had come in secret and left them behind. Paul is assuring them that won’t happen.
But he admonishes them for being shaken in mind, and alarmed by spirits and spoken words. These spirits are still out ther terrorizing people and we need to be on guard for them. People are taken captive by all sorts of weird ideas that are scarcely supported by the Bible. We should only be listening to the apostles, reading what they wrote. They have a way of calming fears.