For this cause we also thank God without ceasing, that, when you received from us the word of the message of God, you accepted it not as the word of men, but, as it is in truth, the word of God, which also works in you who believe.
Which effectually worketh also in you that believe - The word rendered “which” here - ὅς hos - may be referred either to “truth” or to “God.” The grammatical construction will admit of either, but it is not material which is adopted. Either of them expresses a sense undeniably true, and of great importance. The meaning is, that the truth was made efficacious in the minds of all who became true Christians. It induced them to abandon their sins, to devote themselves to God, to lead pure and holy lives, and enabled them to abide the trials and temptations of life; compare notes on Philippians 2:12-13; Hebrews 13:21. The particular illustration here is, that when they embraced the gospel it had such an efficacy on their hearts as to prepare them to meet all the terrors of bitter persecution without shrinking.