If any one saith, that Christ Jesus was given of God to men, as a redeemer in whom to trust, and not also as a legislator whom to obey; let him be anathema.
The Lord Jesus Christ is our King. Who ever heard of a king for whom obedience is optional?!? The very idea is ridiculous. But the fact that we must obey God is in no way contrary the truth that we are justified by grace alone.