John Calvin Commentary 2 Thessalonians 1:4

"so that we ourselves glory in you in the churches of God for your patience and faith in all your persecutions and in the afflictions which ye endure;" — 2 Thessalonians 1:4 (ASV)

So that we ourselves glory in you. He could not have given them higher praise than by saying that he presents them to other churches as an example, for that is the meaning of those words: — We glory in you in the presence of other Churches.

For Paul did not boast of the faith of the Thessalonians out of a spirit of ambition, but because his praise of them might be an encouragement for others to strive to imitate them. He does not say, however, that he glories in their faith and love, but in their patience and faith.

From this it follows that patience is the fruit and evidence of faith. These words should, therefore, be explained in this way: — “We glory in the patience which springs from faith, and we bear witness that it shines out outstandingly in you”; otherwise, the context would not align. And, undoubtedly, nothing sustains us in tribulations as faith does. This is clear enough from the fact that we completely sink as soon as the promises of God leave us.

Therefore, the more progress anyone makes in faith, the more he will be endowed with patience to endure all things with fortitude. On the other hand, weakness and impatience in adversity indicate unbelief on our part. This is especially true when persecutions must be endured for the gospel, for in that situation, the influence of faith reveals itself.