John Calvin Commentary 2 Thessalonians 1:6

"if so be that it is righteous thing with God to recompense affliction to them that afflict you," — 2 Thessalonians 1:6 (ASV)

To appoint affliction. We have already stated why he mentions God's vengeance against the wicked: it is so that we may learn to rest in the expectation of a judgment to come. For God does not yet avenge the wicked, even while it is necessary that they suffer the punishment for their crimes.

Believers, however, at the same time, understand from this that there is no reason why they should envy the momentary and evanescent felicity of the wicked, which will before long be exchanged for a dreadful destruction. What he adds concerning the rest of the pious accords with the statement of Paul (Acts 3:20), where he calls the day of the last judgment the day of refreshing.

In this declaration, however, concerning the good and the bad, he designed to show more clearly how unjust and confused the government of the world would be if God did not defer punishments and rewards until another judgment; for in this way, the name of God would be a dead thing. Therefore, He is deprived of His office and power by all who are not intent on that righteousness of which Paul speaks.

He adds with us, so that he may lend credibility to his doctrine from his own experience of belief; for he shows that he does not philosophize about unknown things, by putting himself into the same condition and rank with them. We know, however, how much more authority is due to those who have, by long practice, been experienced in those things they teach and do not require from others anything but what they themselves are prepared to do. Paul, therefore, does not, while himself in the shade, give instructions to the Thessalonians on how they should fight in the heat of the sun, but, fighting vigorously, exhorts them to the same warfare.