Charles Ellicott Commentary 1 Thessalonians 2:10

"Ye are witnesses, and God [also], how holily and righteously and unblameably we behaved ourselves toward you that believe:" — 1 Thessalonians 2:10 (ASV)

You are witnesses.—Abruptly, without conjunction, the writers add a summary description of their conduct at Thessalonica. Before, they had focused on details; now, they focus on the broad characteristics. As in 1 Thessalonians 2:5, God is appealed to because the readers could only judge the outward propriety of their teachers’ conduct. And it is a moral law that (as Aristotle says), “the righteous man is not he who does acts that in themselves are righteous, but he who does those acts in such a mind as befits righteous men.”

Holily, regarding the inner life; “justly,” regarding the outer life.

Among you who believe—where (if anywhere) we might have been tempted to be lax or exorbitant.