Charles Ellicott Commentary Romans 6:17

"But thanks be to God, that, whereas ye were servants of sin, ye became obedient from the heart to that form of teaching whereunto ye were delivered;" — Romans 6:17 (ASV)

Have obeyed.—Rather, obeyed. (See Note on Romans 6:2.) Similarly, correct “have yielded” to “yielded” in Romans 6:19.

That form of doctrine.—That pattern of teaching, or express moral rule of life.

Delivered you.—Literally, to which you were delivered—to the direction of which you were handed over.