You are witnesses with God, how holy, righteously, and blamelessly we behaved ourselves toward you who believe.
And unblameably - This seems to refer to his duties both to God and man. In reference to all those duties no one could bring a charge against him. Every duty was faithfully performed. This is not a claim to absolute perfection, but it is a claim to consistency of character, and to faithfulness in duty, which every Christian should be enabled to make. Every man professing religion should so live as to be able to appeal to all who have had an opportunity of knowing him, as witnesses that he was consistent and faithful, and that there was nothing which could be laid to his charge.