"But thanks be to God that though you were slaves of sin, you became obedient from the heart to that form of teaching to which you were committed" (Romans 6:17).
Federal Visionists love this verse because it sounds like Paul is saying that obedience can come from our hearts. This is sheer Arminianism.
Our hearts are “more deceitful than all else and desperately sick” (Jeremiah 17:9). This is total depravity. To suggest that our hearts can be obedient is to contradict historic Calvinism.
Notice that Paul does not say, “you became obedient from your heart.” He says, “you became obedient from the heart.” Obviously, this is referring to the heart of Christ because only Jesus’ heart can be obedient.