“Although the Law of God contains a perfect rule of conduct admirably arranged, it has seemed proper to our divine Master to train his people by a more accurate method, to the rule which is enjoined in the Law; and the leading principle in the method is, that it is the duty of believers to present their ‘bodies a living sacrifice, holy and acceptable unto God, which is their reasonable service,’ (Rom. 12:1). Hence he draws the exhortation: ‘Be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect will of God.’ The great point, then, is, that we are consecrated and dedicated to God, and, therefore, should not henceforth think, speak, design, or act, without a view to his glory. What he hath made sacred cannot, without signal insult to him, be applied to profane use. But if we are not our own, but the Lord’s, it is plain both what error is to be shunned, and to what end the actions of our lives ought to be directed. We are not our own; therefore, neither is our own reason or will to rule our acts and counsels. We are not our own; therefore, let us not make it our end to seek what may be agreeable to our carnal nature. We are not our own; therefore, as far as possible, let us forget ourselves and the things that are ours. On the other hand, we are God’s; let us, therefore, live and die to him (Rom. 14:8). We are God’s; therefore, let his wisdom and will preside over all our actions. We are God’s; to him, then, as the only legitimate end, let every part of our life be directed. O how great the proficiency of him who, taught that he is not his own, has withdrawn the dominion and government of himself from his own reason that he may give them to God! For as the surest source of destruction to men is to obey themselves, so the only haven of safety is to have no other will, no other wisdom, than to follow the Lord wherever he leads. Let this, then be the first step, to abandon ourselves, and devote the whole energy of our minds to the service of God. By service, I mean not only that which consists in verbal obedience, but that by which the mind, divested of its own carnal feelings, implicitly obeys the call of the Spirit of God. This transformation (which Paul calls the renewing of the mind, Rom. 12:2; Eph. 4:23), though it is the first entrance to life, was unknown to all the philosophers. They give the government of man to reason alone, thinking that she alone is to be listened to; in short, they assign to her the sole direction of the conduct. But Christian philosophy bids her give place, and yield complete submission to the Holy Spirit, so that the man himself no longer lives, but Christ lives and reigns in him (Gal. 2:20).”
– John Calvin (1509-1564), Institutes of the Christian Religion, III.vii.1.