John Chrysostom
Having shamed them by slavery, frightened them, and stirred them by rewards, the Apostle again encourages his hearers by reminding them of benefactions. In these words he shows that they were freed from great evils, that they were not freed by their own strength, and that the future is more pleasant.
Just as a man who has freed a captive from a cruel tormentor reminds him of that dreadful power, persuading him not to return, so Paul depicts past calamities very clearly. He also speaks of thanksgiving to God.
He says that no human power was needed to free us from all those evils. Rather, thanks be to God, Who both willed and was able to deliver us.
Read more (126 words)
The Apostle rightly said, "you became obedient from the heart." That is, you were not subjected to compulsion or violence, but freely, by your own disposition, you withdrew from sin. This contains both praise and rebuke.
If you came willingly and suffered no compulsion, what excuse or defense can you have when you return again to your former state?
Then, so that you may know that all this did not depend only on their disposition, but also on God's grace, after saying, "you became obedient from the heart," the Apostle added, "to that form of teaching to which you were delivered."
Obedience from the heart shows free will. The word "delivered" hints at God's help. What is this form of teaching? To live rightly and watchfully.