Albert Barnes Commentary 1 Thessalonians 3:7

"for this cause, brethren, we were comforted over you in all our distress and affliction through your faith:" — 1 Thessalonians 3:7 (ASV)

We were comforted over you. (See the notes on 2 Corinthians 1:3 and following; 2 Corinthians 7:6; and 2 Corinthians 7:7).

The sense here is that their steadfastness was a great source of comfort to him in his trials. It was an instance where the holy lives and the fidelity of a people did much, as will always be the case, to lighten the burdens and cheer the heart of a minister of the gospel. In the inevitable trials of the ministerial office, there is no source of comfort more rich and pure than this.