John Calvin Commentary 2 Thessalonians 3:14

"And if any man obeyeth not our word by this epistle, note that man, that ye have no company with him, to the end that he may be ashamed." — 2 Thessalonians 3:14 (ASV)

If any one obeys not. He has already declared previously that he commands nothing but from the Lord. Therefore, the person who would not obey would not be defiant against a mere human, but would be rebellious against God Himself; and accordingly, he teaches that such persons should be severely chastised. And, in the first place, he desires that they be reported to him, so that he may restrain them by his authority; and, secondly, he orders them to be excommunicated, so that, being touched with shame, they may repent. From this we infer that we must not spare the reputation of those who cannot be stopped otherwise than by their faults being exposed; but we must take care to make known their spiritual illnesses to the physician, so that he may endeavor to cure them.

Keep no company. I have no doubt that he refers to excommunication; for, besides the fact that the (ἀταξία) disorder to which he had referred deserved severe chastisement, defiance is an intolerable vice. He had said before, Withdraw yourselves from them, because they live in a disorderly manner (2 Thessalonians 3:6). And now he says, Keep no company, because they reject my admonition. He expresses, therefore, something more by this second expression than by the first; for it is one thing to withdraw from intimate acquaintance with an individual, and quite another to keep completely aloof from his society. In short, those who do not obey after being admonished, he excludes from the common fellowship of believers. By this we are taught that we must use the discipline of excommunication against all obstinate persons who will not otherwise allow themselves to be brought into submission, and they must be branded with disgrace until, having been brought under and subdued, they learn to obey.

That he may be ashamed. It is true, there are other purposes for excommunication—so that the contagion may not spread further, so that the personal wickedness of one individual may not lead to the common disgrace of the Church, and so that the example of severity may induce others to fear (1 Timothy 5:20); but Paul touches only upon this one: that those who have sinned may by shame be compelled to repentance.

For those who please themselves in their vices become more and more obstinate; thus sin is nourished by indulgence and dissimulation. This, therefore, is the best remedy—when a feeling of shame is awakened in the mind of the offender, so that he begins to be displeased with himself. Indeed, it would be a small point gained to have individuals made ashamed; but Paul looked toward further progress—when the offender, confounded by discovering his own baseness, is led in this way to complete reformation. For shame, like sorrow, is a useful preparation for hating sin. Therefore, all who become self-indulgent must, as I have said, be restrained by this bridle, lest their audacity should be increased because of impunity.