John Chrysostom

"Grace be unto you, and peace." Do you perceive that the very commencement of his Epistle is with encomiums? "We give thanks to God always for you all, making mention of you in our prayers." For to give thanks to God for them is the act of one testifying to their great advancement, when they are not only praised themselves, but God also is thanked for them, as Himself having done it all. He teaches them also to be moderate, all but saying, that it is all of the power of God. …

Homily on 1 Thessalonians 1 ↗

Theophylact of Ohrid

Immediately after the praise follows glory to God. For by thanking God for them, he shows that they have fulfilled everything by which God is glorified. But at the same time he also teaches humility, since everything is accomplished by God. That he thanks God is a consequence of their virtues; and that he remembers them in his prayers is due to his love for them.

Commentary on 1 Thessalonians ↗

Thomas Aquinas

Then when Paul says, "we give thanks," he begins the letter's message: first, he commends them for their past perseverance; secondly, he urges them to act well even in the future (4:1). In addition, Paul first gives thanks in general for their blessings; secondly, he remarks upon their blessings in particular matters (1:4). In treating the first point he does two things. First, he offers thanksgiving; secondly, he indicates the reason for the thanksgiving (1:3). …

Commentary on 1 Thessalonians ↗