By whom we have received grace and apostleship, for obedience to the faith among all nations, for his name:
Romans 1:5 (KJV)
Obedience in the new covenant is obedience to the faith. Rather than trying to live by the law, our obedience is our commitment to right believing. We are obedient when we believe what God says about us which enables the Holy Spirit to work on the inside of us, shaping us more fully into who God has called us to be.