NOTES for Th1 3:2-3
The church in Thessalonica was undergoing rather serious persecutions, which became known to other churches as well. That is why Paul hurries to support the Thessalonian brothers, reminding them that for a Christian in the fallen world persecution is inevitable and, in general, normal. Of course, the issue is not always persecution in the literal sense, as, judging by the apostle's words, it was in Thessalonica; but rejection always takes place, both from secular people ("Gentiles") and from religious people ("Jews"). The Savior Himself warned His followers of this during His earthly ministry.
Often the point is not some special malice on the part of the persecutors, though that happens too, but simply the incommensurability and incomparability of the Kingdom and the fallen world. And not because this world is natural, but because it is fallen. The problem is not nature as such, but that people to whom God offered another law and another way of existing in His world chose life according to the law of nature, a law intended not for human beings but for the animal kingdom.
But a human being cannot become a normal animal by definition; he can only become a human being who does not answer to his own divine calling and divine definition, which is far worse. And in such a state every manifestation of the Kingdom objectively becomes destructive for him, if not for his outward life, then certainly for his inner life. The very fact that there exists in the world an alternative to the laws of the natural world, which fallen humanity considers its own because it predominantly feels itself to be animal, already deprives a person of peace.
The world must be one; it must live by one set of laws; there is and must be no alternative to the existing order. In this way a person becomes aware of that natural totality of the world of nature which animals feel instinctively and within which they live, of course without any reflection and without any discomfort, from which a person cannot rid himself however much he may wish to.
Of course, thinking about the existing order of things is in itself a purely human property connected with the spiritual principle in a person, but fallen humanity does not much like doing this precisely because it has no desire at all to remember itself as a spiritual being. Culture, and especially religion, can sometimes remind a person of who he truly is, but here everything is still not unambiguous; something can be understood in one's own way, something can simply be ignored, since all culture and even religion still belong to the fallen world. But the manifestation of the Kingdom is quite another matter. It vividly and clearly reveals its otherworldliness.
The alternative becomes obvious, intensifying the anxiety and the desire to make it either not exist at all or at least not be so noticeable. Hence the inevitability of the rejection of Christ and the Kingdom, and therefore of Christians, if they remain Christians not only in name. Sometimes such rejection stays within the bounds of propriety, but it can also go beyond them, especially when there are many witnesses and the light of the Kingdom shines more brightly than usual. The Thessalonian church found itself in just such a situation, and Paul supports it in his letter: for persecutions show precisely that the Thessalonian Christians' witness is in good order.