“How can we understand righteousness as the positive opposite of sin unless we construe it as the opposite of what sin is? And if sin is the transgression of the law, righteousness must be conformity to the law.”     
-John Murray  from Principles of Conduct


“If Paul thought of himself as released from obligation to the law of God, how could he ever have confessed as a believer, 'I consent unto the law that it is good ... I delight in the law of God after the inward man . . . Consequently then I myself with the mind serve the law of God' (Romans 7: 16, 22, 25)?”     
-John Murray  from Principles of Conduct
                              

“The obligation of this law (The Moral Law) upon the Christian is immutable as the throne of God. What can annul the necessary relation of a creature to his Creator ? The additional bond of redemption strengthens, not annihilates, the original obligation. Do we cease to be creatures by becoming new creatures ? And are we not therefore still bound to personal obedience by the sovereign authority of God ? Or does the obligation of the law
lose its force by being conveyed to us through the hands of Christ—himself Lord of all, and standing to us in the most endearing and authoritative relation ? Why, we may ask, do men wish to be rid of this rule ?”
-Charles Bridges
 

“...when Paul describes his most characteristic self, the self that he most centrally and fundamentally is as one united to Christ in the virtue of his death and the power of his resurrection (cf. Romans 6: 2-6), he describes himself as delighting in the law of God and serving that law with his mind. This service is one of bondservice, of commanded commitment; and yet it is not the bondservice of enforced and unwilling servitude. It is service constrained by delight and consent in the deepest recesses of heart and mind and will. It is total commitment, but it is the commitment also of spontaneous delight. The restraint which Paul deplores in this context and which compels him to exclaim 'O wretched man that I am' (Romans 7: 24) is not the restraint which the law of God imposes, but the restraint arising from the lack of conformity to it, that he wills the good but does not carry it into effect. The burden he bemoans is not the law but that which is its contradiction, the other law in his members warring against the law of his mind (Romans 7:23).”        
 -John Murray  from Principles of Conduct
 

“The uses of the law as a rule of life_are most efficient means of promoting stedfastness and consistency. Being "written in the heart," it affords to the Christian a continual touchstone of sincerity. He has "the testimony of his conscience," that he "consents to the law that it is good;" that he "delights in it after the inward man;" that he "esteems all God's commandments concerning all things to be right;" that he counts his want of perfect conformity to it the sin of every moment; that he is satisfied with no attainment short of being "holy, as he that hath called him is holy," and "perfect, as his Father which is in heaven is perfect."
-Charles Bridges